What changed in this filing

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Item 9A. Controls and Procedures

2025-03-31 compared with 2024-03-21 · 1031 added, 266 removed, 632 unchanged (67% of the section changed)

9 unchanged sentences

Our management is responsible for establishing and maintaining adequate internal control over financial reporting.

Internal control over financial reporting is a process designed to provide reasonable assurance of the reliability of financial reporting and of the preparation of financial statements for external reporting purposes, in accordance with U.S.

Internal control over financial reporting is a process designed to provide reasonable assurance of the reliability of financial reporting and of the preparation of consolidated financial statements for external reporting purposes, in accordance with U.S.

generally accepted accounting principles.

Internal control over financial reporting includes policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect transactions and disposition of assets;

(2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with U.S.

(2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of consolidated financial statements in accordance with U.S.

generally accepted accounting principles, and that receipts and expenditures are being made only in accordance with the authorization of its management and directors;

and (3) provide reasonable assurance regarding the prevention or timely detection of unauthorized acquisition, use, or disposition of our assets that could have a material effect on its financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements.

6 unchanged sentences

Attestation Report of the Registered Public Accounting Firm

This Annual Report on Form 10-K does not include an attestation report of our registered public accounting firm due to an exemption established by the JOBS Act for “emerging growth companies.”

As a non-accelerated filer, we are not required to provide an attestation report of our independent registered public accounting firm on the effectiveness of our internal control over financial reporting.

Changes in Internal Control over Financial Reporting

10 unchanged sentences

Terminate (2)

November 9, 2023

January 23, 2024 – January 23, 2025

October 18, 2024

July 8, 2024 - July

Up to 350,000 shares to be sold

1 unchanged sentence

Chief Executive Officer

November 9, 2023

July 8, 2024 - July 31, 2025

Up to 350,000 shares to be sold

Chief Financial Officer

Terminate (3)

November 9, 2023

October 7, 2023 – October 16, 2024

Up to 50,000 shares to be sold

Chief Financial Officer

November 9, 2023

July 15, 2024 - July 16, 2025

Up to 50,000 shares to be sold

Chief Business Officer

Terminate (4)

November 9, 2023

January 16, 2024 – December 31, 2024

Up to 29,168 shares to be sold

Chief Business Officer

November 9, 2023

July 17, 2024 - July 31, 2025

October 18, 2024

February 16, 2025 – July 27, 2026

Up to 350,000 shares to be sold

1 unchanged sentence

President of Science and Technology

Terminate (5)

November 21, 2024

3 unchanged sentences

President of Science and Technology

November 9, 2023

July 22, 2024 - July 23, 2025

December 18, 2024

March 27, 2025 to December 12, 2025

Up to 100,756 shares to be sold

1 unchanged sentence

(1) Except as indicated by footnote, each trading arrangement permitted or permits transactions through and including the earlier to occur of (a) the completion of all purchases or sales or (b) the date listed in the table.

(2) Represents the modification, as described in Rule 10b5-1(c)(1)(iv) under the Exchange Act, of a written trading arrangement adopted on August 30, 2023 that was intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act.

(3) Represents the modification, as described in Rule 10b5-1(c)(1)(iv) under the Exchange Act, of a written trading arrangement adopted on June 8, 2023 that was intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act.

(4) Represents the modification, as described in Rule 10b5-1(c)(1)(iv) under the Exchange Act, of a written trading arrangement adopted on September 5, 2023 that was intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act.

(5) Represents the modification, as described in Rule 10b5-1(c)(1)(iv) under the Exchange Act, of a written trading arrangement adopted on August 24, 2023 that was intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act.

Termination of 2023 At-The-Market Offering

On March 16, 2023, we entered into the 2023 Sales Agreement with the Sales Agent, pursuant to which we could, from time to time, sell shares of our common stock having an aggregate offering price of up to $100.0 million through the Sales Agent, as our agent, or the 2023 ATM Offering.

In connection with the 2023 ATM Offering, we filed a prospectus, dated March 16, 2023, with the 2023 Registration Statement, or the 2023 ATM Prospectus.

Between March 16, 2023 and March 21, 2024, we sold an aggregate of 5,018,969 shares of common stock pursuant to the 2023 Sales Agreement for aggregate gross proceeds of approximately $99.9 million, thereby selling the total amount available under the 2023 Sales Agreement.

Pursuant to the terms of the 2023 Sales Agreement, effective March 21, 2024, or the Termination Date, we terminated the 2023 Sales Agreement, and we have discontinued all offers and sales of shares of our common stock under the 2023 Sales Agreement and the 2023 ATM Prospectus.

All of the continuing obligations under the 2023 Sales Agreement will be terminated as of the Termination Date, other than those provisions which expressly survive termination as provided in the 2023 Sales Agreement.

We are not subject to any termination penalties related to the termination of the 2023 Sales Agreement.

A copy of the 2023 Sales Agreement was filed as Exhibit 1.2 to our Registration Statement on Form S-3 (File No.

333-270599) filed with the SEC on March 16, 2023.

(2) Represents the modification, as described in Rule 10b5-1(c)(1)(iv) under the Exchange Act, of a written trading arrangement adopted on November 9, 2023 that was intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act.

Disclosure Regarding Foreign Jurisdictions that Prevent Inspections.

1 unchanged sentence

Directors, Executive Off icers and Corporate Governance.

Except as set forth below, the information required by this item is incorporated by reference from our definitive Proxy Statement to be filed with the SEC in connection with our 2024 Annual Meeting of Stockholders within 120 days after the end of the fiscal year ended December 31, 2023.

We have adopted a Code of Business Conduct and Ethics that applies to all of our directors, officers and employees, including our principal executive officer and principal financial officer.

The Code of Business Conduct and Ethics is posted on our website at http://investors.cabalettabio.com/corporate-governance/governance-highlights .

We intend to satisfy the disclosure requirement under Item 5.05 of Form 8-K regarding an amendment to, or waiver from, a provision of this Code of Business Conduct and Ethics by posting such information on our website, at the address and location specified above and, to the extent required by the listing standards of The Nasdaq Global Select Market, by filing a Current Report on Form 8-K with the SEC, disclosing such information.

The following table sets forth information about our directors and executive officers as of March 27, 2025.

Positions and Offices Held with Cabaletta

Officer/Director

Class and Year in Which Term Will Expire

Executive Officers

Steven Nichtberger, M.D.

Chief Executive Officer, President, Chairman of the Board of Directors and Director

Class III—2025

Binder, Ph.D.

President, Science and Technology

Anup Marda, MBA

Chief Financial Officer

Chang, M.D., M.P.H.

Chief Medical Officer

Michael Gerard, J.D.

General Counsel and Secretary

Arun Das, M.D.

Chief Business Officer

Non-Employee Directors

Mark Simon, MBA (1)(2)(3)

Class III—2025

Scott Brun, M.D.

Shawn Tomasello, MBA (2)

Catherine Bollard, MBChB, M.D.

Class II—2027

Richard Henriques, MBA (1)(2)

Class II—2027

(1) Member of the Audit Committee.

(2) Member of the Compensation Committee.

(3) Member of the Nominating and Corporate Governance Committee.

Executive Officers

Steven Nichtberger, M.D.

Nichtberger has served as our Chief Executive Officer, President and Chairman of our board of directors since our founding in 2017.

He is also a Professor of Professional Practice in the Vagelos LSM program and adjunct professor at The Wharton School of the University of Pennsylvania in addition to being a member of the board of directors of the BioAdvance Greenhouse Fund.

Previously, Dr.

Nichtberger served as president, chief executive officer, and a member of the board of directors of Tengion, Inc.

from 2004 to 2011.

In 2008, his leadership was recognized nationally with the National Ernst & Young Entrepreneur of the Year Award for emerging companies.

Earlier in his career, Dr.

Nichtberger served as the head of global marketing for Merck and in various commercial operating roles at the company from 1995 to 2003.

He has previously served as a member of the boards of directors of the Alliance for Regenerative Medicine (as a founding member), Pennsylvania Bio (including as chairman), and Biotechnology Industry Organization.

From 2008 to 2019, he was a member of the board of overseers for the School of Arts & Sciences at the University of Pennsylvania.

Nichtberger received his M.D.

from the State University of New York at Buffalo, his B.S.

from The Wharton School at the University of Pennsylvania and his B.A.

from the University of Pennsylvania.

He completed internship, residency and fellowship in the Department of Medicine and the Division of Cardiology of the Mount Sinai Medical Center in New York.

We believe Dr.

Nichtberger is qualified to serve as a member and Chairman of our board of directors because of his scientific and medical background as well as his corporate leadership experience.

Binder, Ph.D.

Binder joined our company in February 2019 as our Executive Vice President, Science and Technology and was appointed President, Science and Technology in January 2022.

Binder is an R&D executive with specialized expertise in the discovery and early clinical development and optimization of engineered T cell therapies.

Prior to joining Cabaletta, Dr.

Binder was the Chief Technology Officer of Adaptimmune Therapeutics Plc from March 2016 to January 2019, where she ultimately led the research team focusing on understanding mechanisms of tumor response and resistance and translating this understanding to next generation products and clinical study designs.

In prior roles, from March 2011 to February 2016, she established and led the translational research group, in addition to the manufacturing and quality teams including oversight of the buildout of an in-house manufacturing facility.

Earlier in her career, Dr.

Binder served as Director of Operations for the Translational Research Program at the University of Pennsylvania, where she where she progressed multiple investigational new drug submissions for novel engineered T-cell therapies in HIV and oncology, including the CD19 CAR IND acquired by Novartis (now Kymriah), the first human gene editing IND, and three TCR engineered T cell therapy studies in oncology and HIV.

Prior to that, she served as the

Director of Scientific Affairs at VIRxSYS Corporation in Gaithersburg Maryland where she supported the development of the first clinical lentiviral vector used in humans, for the application of engineered T cell therapy for HIV.

In addition, Dr.

Binder has served on the Board of Directors of Instil Bio (Nasdaq:

TIL), a clinical-stage biopharmaceutical company focused on developing a pipeline of novel therapies including a lead PD-L1xVEGF bispecific antibody for solid tumors, since July 2020, and as a member of the Scientific Advisory Board for Immatics, which is a publicly traded company developing engineered T cell immunotherapy for cancer, since July 2020.

Binder studied viral immunology and translational research at the Johns Hopkins University in Baltimore, Maryland where she earned a Ph.D.

in Cellular and Molecular Medicine in 2002.

She has authored over 30 publications in the field, including top international journals such as “Science”, and “Nature Medicine”.

She is a recognized leader in the biotechnology sector for the translational and clinical advancement of novel T cell therapies for patients with serious diseases.

Anup Marda, MBA.

Marda joined our company in January 2019 as our Chief Financial Officer.

From April 2001 to January 2019, Mr.

Marda held positions at Bristol-Myers Squibb, including, most recently, as Vice President, Head of Global Corporate Financial Planning & Analysis, and previously as Head of Finance, R&D Operations and Head of Finance, R&D Portfolio Management and Global Medical from 2014 to 2018.

Prior to this, Mr.

Marda held the role of Executive Director, U.S.

Pharmaceuticals from 2012 to 2014 and Assistant Treasurer, Capital Markets from 2008 to 2012.

Marda received his MBA from the Krannert School of Business of Purdue University and his B.Tech in Chemical Engineering from the Indian Institute of Technology Bombay.

Chang, M.D., M.P.H.

Chang joined our company in June 2019 as our Chief Medical Officer.

From June 2015 to May 2019, he was Senior Vice President and Head, Inflammation, Autoimmunity & Neuroscience, or IA&NS, Global Medicines Development at AstraZeneca Pharmaceuticals LP, where he oversaw development projects of both biologics and small molecules in a variety of indications and led the late-stage clinical development organization for IA&NS.

From October 2007 to June 2015, Dr.

Chang served in various positions at GlaxoSmithKline plc, including VP and Head, Immuno-Inflammation, Clinical Development.

While at AstraZeneca and GlaxoSmithKline, he provided leadership in driving the clinical development and registration of the only two products approved for systemic lupus erythematosus in the US in over 60 years.

He received his M.D.

from New York University School of Medicine, his M.P.H.

from Emory University and his B.S.

from Yale University.

Chang completed his internship and residency in internal medicine at the New York Hospital—Cornell University Medical Center and fellowship in rheumatology at the Hospital for Special Surgery—Cornell University Medical Center.

Michael Gerard, J.D.

Gerard joined our company in September 2021 as our General Counsel and Secretary.

Prior to joining Cabaletta, Mr.

Gerard served as Associate General Counsel of Spark Therapeutics, Inc., or Spark, from September 2020 to August 2021.

Prior to Spark, Mr.

Gerard served in various legal roles at Sandoz, Inc., a division of the Novartis Group, beginning in 2013, with the most recent role being Executive Director, Associate General Counsel, Business Development and Licensing, Strategy and Portfolio.

Earlier in his career, Mr.

Gerard served as Assistant General Counsel at Aramark and as a litigator at the law firms of Morrison & Foerster, LLP and K&L Gates, LLP in New York.

Gerard received a B.A.

in Political Science from the University of Michigan, Ann Arbor and a J.D.

from Cornell Law School.

Arun Das, M.D.

Das joined our company in July 2019 after serving as a consultant to the company since 2017, and served in several roles, most recently Executive Director of New Product Planning and Business Development, prior to being appointed Chief Business Officer in January 2022.

He is also a Lecturer in the Health Care Management Department at the Wharton School of the University of Pennsylvania.

Prior to joining Cabaletta, Dr.

Das was a resident physician in General Pediatrics at the Children’s Hospital of Philadelphia from June 2018 to June 2019.

Previously, he was an investment banking analyst in the healthcare group at Goldman Sachs from 2010 to 2012.

In addition, Dr.

Das has spent multiple years consulting in business development and operations for several start-ups in the biotechnology space.

Das received his M.D.

from Johns Hopkins University School of Medicine and a B.A.

dual degree from the University of Pennsylvania.

Non-Employee Directors

Mark Simon, MBA .

Simon joined our board of directors in October 2018.

He is a Strategic Advisor since 2020 to the Founder and CEO of Sun Pharmaceutical Industries Ltd., which is the largest pharmaceutical company in India, and a board observer of Sun Pharma Advanced Research Company Ltd., both public companies in India, where Mr.

Simon is focused on accelerating their innovation initiatives.

He is also a consultant to Stifel Nicolaus & Company (NYSE:

SF) and co-founder of Torreya Partners, LLC, a global investment banking firm serving companies in the life sciences industry that Stifel acquired in 2023.

Prior to co-founding Torreya, Mr.

Simon was a managing director and head of life sciences investment banking at Citigroup from 2002 to 2005 where he covered global pharmaceutical companies with a focus on large-capitalization players in the U.S., Europe and Japan.

Prior to Citigroup, Mr.

Simon served as a Managing Director at Robertson Stephens in San Francisco and New York where he was responsible for covering the biotechnology investment banking sector.

During his tenure overseeing the group, he was involved in raising 45% of all biotechnology dollars raised in the U.S.

from 1999-2001.

Prior to joining the investment banking group, Mr.

Simon was a senior biotechnology research analyst at Robertson Stephens, and was named a Wall Street All-Star Analyst for three years in a row.

He began his career at Kidder Peabody as a biotechnology research associate in 1984 and participated in the IPO of Genzyme and the early financings of companies such as Amgen.

Simon currently serves on the boards of directors of several disease advocacy and philanthropic foundations in the oncology, CNS/neuroscience and metabolic areas.

He previously served on the board of directors of Portage Biotech Inc.

PRTG) until April 2024.

Simon received his MBA from Harvard Business School and his B.A.

from Columbia College.

We believe that Mr.

Simon is qualified to serve on our board of directors because of his extensive experience of over 35 years in the life sciences industry and biotechnology and specialty pharmaceutical transactions.

Scott Brun, M.D.

Brun joined our board of directors in June 2021.

Brun is currently President at Gold Mast Consulting, LLC, an advisory firm he founded in 2019 to provide technical advice and strategic guidance related to biopharmaceutical research and development, pipeline portfolio management, commercialization of new therapeutics and strategic communications related to R&D activities.

Brun serves as a Venture Partner at Abingworth LLP and a Senior Medical Advisor to Launch Therapeutics.

Prior to his current roles, Dr.

Brun had two decades of experience in various leadership roles at AbbVie, Inc., including 15 years at the predecessor company, Abbott Laboratories.

The majority of his career has been focused on leading teams and clinical development organizations across a broad variety of therapeutic areas including autoimmune, neurologic, and renal among others.

He was most recently Corporate Vice President of Scientific Affairs and Head of AbbVie Ventures, a corporate venture fund responsible for investment opportunities within AbbVie’s R&D therapeutic areas as well as technology platforms of interest from 2016 to 2019.

Previously, Dr.

Brun served as Corporate Vice President and Head of Pharmaceutical Development at AbbVie from 2013 to 2016.

During his tenure at AbbVie, Dr.

Brun oversaw a global organization with responsibilities for AbbVie’s entire portfolio of early and late-stage clinical pre-registration pipeline compounds as well as marketed compounds within oncology, neurology, immunology, renal, infectious disease, and women’s and men’s health therapeutic areas.

Prior to joining AbbVie, Dr.

Brun spent over 15 years at Abbott Laboratories, where he held positions of increasing leadership responsibility in drug development within the R&D organization.

Brun is a member of the boards of directors of Axial Biotherapeutics, Inc.

and Trishula Therapeutics, Inc., both private, clinical-stage biopharmaceutical companies, Jasper Therapeutics, Inc.

JSPR) a biotechnology company focused on targeting mast cells and stem cells to treat chronic diseases and Forte Biosciences, Inc.

FBRX) a preclinical-stage company focused on autoimmune diseases.

Previously, Dr.

Brun served as a Senior Advisor to the business development team at Horizon Therapeutics plc (Nasdaq:

HZNP) from 2020 to 2023.

Brun received his B.S.

in Biochemistry from the University of Illinois at Urbana-Champaign and earned his M.D.

from the Johns Hopkins University School of Medicine.

He completed his residency in ophthalmology at the Massachusetts Eye and Ear Infirmary, Harvard Medical School.

We believe Dr.

Brun is qualified to serve as a member of our board of directors because of his scientific background and significant experience in clinical and research efforts.

Shawn Tomasello, MBA .

Tomasello joined our Board of Directors in July 2023.

She is currently Chief Executive Officer at CoRegen, Inc., a private company.

Prior to her current role, Ms.

Tomasello served as the Chief Commercial Officer of Kite Pharma, where she oversaw the global commercialization of Yescarta, from 2015 to 2018 including through its acquisition by Gilead for $11.9 billion in October 2017.

She was previously Chief Commercial Officer at Pharmacyclics, where she led commercial and medical affairs activities for Imbruvica®, a first-in-class treatment for hematologic malignancies, from August 2014 until its acquisition by AbbVie for $21.0 billion in August 2015.

Prior to Pharmacyclics, Ms.

Tomasello served in leading commercial roles with multiple major pharmaceutical companies, including Celgene as President of the Americas Hematology and Oncology, where she led the company through five successful product launches encompassing 11 indications and played a critical role in acquisitions.

At Genentech for 14 years prior, Ms.

Tomasello was the National Director of Hematology for Rituxan.

She currently serves on the board of directors of AlloVir, Inc.

ALVR) since March 2022, 4D Molecular Therapeutics Inc.

FDMT) since November 2020 and Centrexion Therapeutics Corp., a private, clinical-stage biopharmaceutical company, since 2017.

She previously served as a board member of TCR2 Therapeutics Inc.

TCRR) until June 2023, Urogen Pharma Ltd (Nasdaq:

URGN) until 2022, Mesoblast, Ltd.

MESO) until August 2022, Clementia Pharmaceuticals, Diplomat Pharmacy, Inc.

until 2020, Abeona Therapeutics (Nasdaq:

ABEO) until 2020, Principia Biopharma until 2020, and Gamida Cell Ltd.

GMDA) until 2024, as well as several private boards.

On such boards, she at various times has served and serves on the Compensation, Nominating and Corporate Governance, Compliance, and Transaction committees.

Tomasello received her B.S.

in Marketing from the University of Cincinnati and her M.B.A.

from Murray State University in Kentucky.

We believe Ms.

Tomasello is qualified to serve as a member of our Board of Directors because of her experience serving in various commercial roles in the life sciences industry.

Catherine Bollard, MBChB, M.D.

Bollard joined our board of directors in April 2019.

She currently serves as Senior Vice President and Chief Research Officer and Director of the Center for Cancer and Immunology Research at the Children’s National Research Institute (CNRI).

She is also a faculty member of the Division of the Blood and Marrow Transplantation at CNH.

Since 2013, Dr.

Bollard has served as a tenured Professor of Pediatrics and Microbiology, Immunology and Tropical Medicine at the George Washington University and is the Associate Center Director (ACD) for Translational Research and Innovation within the George Washington Cancer Center.

Prior to her move in 2013, Dr.

Bollard was Professor of Pediatrics, Medicine and

Immunology at Baylor College of Medicine.

She is a past president of the International Society for Cell Therapy (ISCT), and she served on the Cellular, Tissues and Gene Therapy Advisory Committee of the FDA until 2019.

Bollard chaired the Non-Hodgkin’s Lymphoma Committee of the Children’s Oncology Group from 2012 to 2020 and in 2021 became the President of the Foundation for the Accreditation of Cellular Therapy (FACT).

Bollard was the scientific co-founder of Catamaran Bio, a company developing novel, off-the-shelf chimeric antigen receptor (CAR)-NK cell therapies designed to treat a broad range of cancers and served on its Scientific Advisory Board until 2024.

Bollard was previously on the board of directors and subsequently the Scientific Advisory Board of Mana Therapeutics.

She currently serves on the SAB of Minovia Tx Ltd and serves as Chair of the DSMB for SOBI.

Bollard also serves on the board of directors for Alliance for Regenerative Medicine and a nonprofit organization she co-founded called Access4Kids.

Bollard received her medical degree (MBChB) and her doctor of medicine (MD) from the University of Otago Medical School in New Zealand.

We believe Dr.

Bollard is qualified to serve as a member of our board of directors because of her scientific background and significant experience in clinical and translational research efforts.

Richard Henriques, MBA.

Henriques joined our board of directors in February 2019.

Since 2015, he has been a senior fellow at the Center for High Impact Philanthropy at the University of Pennsylvania, with a focus on impact investing.

From 2010 to 2014, Mr.

Henriques was the Chief Financial Officer of the Bill & Melinda Gates Foundation, where he was responsible for finance and accounting, financial planning and analysis, strategic planning, measurement and evaluation, program related investments and information technology.

From 1981 to 2008, Mr.

Henriques held positions at Merck & Co., Inc., including as Senior Vice President of Finance for Global Human Health, Vice President and Corporate Controller, and Principal Accounting Officer.

Henriques serves on the boards of directors or trustees of the Bucks County Playhouse, International Vaccine Institute, Heritage Conservancy, Delaware Canal 21, Fisherman’s Mark and The Franklin Institute.

Henriques served on the board of directors of Arbutus Biopharma Corporation (Nasdaq:

ABUS) from December 2014 to February 2025.

Henriques received his MBA from the Wharton School of the University of Pennsylvania and a BA from the University of Pennsylvania.

We believe that Mr.

Henriques is qualified to serve as a member of our board of directors because of his extensive corporate leadership experience and expertise in finance and investment management.

Family Relationships and Legal Proceedings

There are no family relationships between or among any of our directors or executive officers.

Our executive officers are appointed by, and serve at the discretion of, our board of directors.

The principal occupation and employment during the past five years of each of our directors was carried on, in each case except as specifically identified above, with a corporation or organization that is not a parent, subsidiary or other affiliate of us.

There is no arrangement or understanding between any of our directors and any other person or persons pursuant to which he or she is to be selected as a director.

There are no material legal proceedings to which any of our directors, officers or affiliate, any owner of record or beneficially of more than five percent of any class of our voting securities, or any associate of any such director, officer, affiliate, or security holder is a party adverse to us or any of our subsidiaries or in which any such person has a material interest adverse to us or our subsidiary.

Board Committees

Our board of directors has established an audit committee, a compensation committee, and a nominating and corporate governance committee.

Each of the audit committee, compensation committee, and nominating and corporate governance committee operates under a charter that satisfies the applicable standards of the SEC and Nasdaq.

Our board of directors has also established a science and technology committee, an advisory committee of the board of directors which operates under a charter duly adopted by the board of directors.

Each such committee reviews its respective charter at least annually.

A current copy of the charter for each of the audit committee, compensation committee, nominating and corporate governance committee and science and technology committee is posted on the corporate governance section of our website, www.cabalettabio.com/investors/corporate-governance/governance-documents .

From time to time, our board of directors may establish certain committees for scientific, business or other matters.

Audit Committee

Scott Brun, M.D., Richard Henriques, MBA and Mark Simon, MBA serve on the audit committee, which is chaired by Richard Henriques, MBA.

Our board of directors has determined that each member of the audit committee is “independent” for audit committee purposes as that term is defined in the rules of the SEC and the applicable Nasdaq rules, and each has sufficient knowledge in financial and auditing matters to serve on the audit committee.

Our board of directors has designated Mr.

Henriques as an “audit

committee financial expert,” as defined under the applicable rules of the SEC.

During the fiscal year ended December 31, 2024, the audit committee met seven times.

The audit committee’s responsibilities include:

• appointing, approving the compensation of, and assessing the independence of our independent registered public accounting firm;

• pre-approving auditing and permissible non-audit services, and the terms of such services, to be provided by our independent registered public accounting firm;

• reviewing the overall audit plan with our independent registered public accounting firm and members of management responsible for preparing our financial statements;

• reviewing and discussing with management and our independent registered public accounting firm our annual and quarterly financial statements and related disclosures as well as critical accounting policies and practices used by us;

• coordinating the oversight and reviewing the adequacy of our internal control over financial reporting;

• establishing policies and procedures for the receipt and retention of accounting-related complaints and concerns;

• recommending based upon the audit committee’s review and discussions with management and our independent registered public accounting firm whether our audited financial statements and our related disclosures under the “Management’s Discussion and Analysis” section shall be included in our 2024 Annual Report;

• monitoring the integrity of our financial statements and our compliance with legal and regulatory requirements as they relate to our financial statements and accounting matters;

• preparing the audit committee report required by SEC rules to be included in our annual proxy statement;

• reviewing all related person transactions for potential conflict of interest situations and approving all such transactions;

• reviewing quarterly earnings releases;

• discussing the Company’s risk assessment and management guidelines, including the Company’s major financial risk exposures, cybersecurity risks and the steps that the Company’s management has taken to monitor and control such exposures and risks.

All audit and non-audit services, other than de minimis non-audit services, to be provided to us by our independent registered public accounting firm must be approved in advance by our audit committee.

Compensation Committee

Richard Henriques, MBA, Mark Simon, MBA and Shawn Tomasello, MBA serve on the compensation committee, which is chaired by Mark Simon, MBA.

Our board of directors has determined that each member of the compensation committee is “independent” as defined in the applicable Nasdaq rules.

During the fiscal year ended December 31, 2024, the compensation committee met four times.

The compensation committee’s responsibilities include:

• annually reviewing and recommending to the board of directors corporate goals and objectives relevant to the compensation of our chief executive officer;

• evaluating the performance of our chief executive officer in light of such corporate goals and objectives and based on such evaluation (i) recommending to the board of directors the cash compensation of our chief executive officer and (ii) reviewing and approving grants and awards to our chief executive officer under equity-based plans;

• reviewing and approving the compensation of our other executive officers;

• reviewing and establishing our overall management compensation, philosophy, and policy;

• overseeing and administering our compensation and similar plans;

• evaluating and assessing potential and current compensation advisors in accordance with the independence standards identified in the applicable Nasdaq rules;

• reviewing and making recommendations to our board of directors about our policies and procedures for the grant of equity-based awards;

• preparing the compensation committee report required by SEC rules, if and when required, to be included in our annual proxy statement;

• reviewing and discussing annually with management our “Compensation Discussion and Analysis,” if and when required, to be included in our annual proxy statement;

• reviewing and approving the retention or termination of any consulting firm or outside advisor to assist in the evaluation of compensation matters.

Nominating and Corporate Governance Committee

Catherine Bollard, MBChB, M.D., Scott Brun, M.D., and Mark Simon, MBA, serve on the nominating and corporate governance committee, which is chaired by Scott Brun, M.D.

Our board of directors has determined that each member of the nominating and corporate governance committee is “independent” as defined in the applicable Nasdaq rules.

During the fiscal year ended December 31, 2024, the nominating and corporate governance committee met two times.

The nominating and corporate governance committee’s responsibilities include:

• developing and recommending to the board of directors criteria for board and committee membership;

• establishing procedures for identifying and evaluating board of director candidates, including nominees recommended by stockholders;

• reviewing the composition of the board of directors to ensure that it is composed of members containing the appropriate skills and expertise to advise us;

• identifying individuals qualified to become members of the board of directors;

• recommending to the board of directors the persons to be nominated for election as directors and to each of the board’s committees;

• reviewing and discussing with the board of directors corporate succession plans for our chief executive officer and other key officers;

• developing and recommending to the board of directors a code of business conduct and ethics and a set of corporate governance guidelines;

• overseeing the evaluation of our board of directors.

The nominating and corporate governance committee considers candidates for board of directors membership suggested by its members and the chief executive officer.

Additionally, in selecting nominees for directors, the nominating and corporate governance committee will review candidates recommended by stockholders in the same manner and using the same general criteria as candidates recruited by the committee and/or recommended by our board of directors.

Any stockholder who wishes to recommend a candidate for consideration by the committee as a nominee for director should follow the procedures described in our proxy statement under the heading “Stockholder Proposals.” The nominating and corporate governance committee will also consider whether to nominate any person proposed by a stockholder in accordance with the provisions of our bylaws relating to stockholder nominations as described in our proxy statement under the heading “Stockholder Proposals.”

Identifying and Evaluating Director Nominees.

Our board of directors is responsible for filling vacancies on our board of directors and for nominating candidates for election by our stockholders each year in the class of directors whose term expires at the relevant annual meeting.

The board of directors delegates the selection and nomination process to the nominating and corporate governance committee, with the expectation that other members of the board of directors, and of management, will be requested to take part in the process as appropriate.

Generally, the nominating and corporate governance committee identifies candidates for director nominees in consultation with management, through the recommendations submitted by stockholders or through such other methods as the nominating and corporate governance committee deems to be helpful to identify candidates.

Once candidates have been identified, the nominating and corporate governance committee confirms that the candidates meet all of the minimum qualifications for director nominees established by the nominating and corporate governance committee.

The nominating and corporate governance committee may gather information about the candidates through interviews, detailed questionnaires, comprehensive background checks or any other means that the nominating and corporate governance committee deems to be appropriate in the evaluation process.

The nominating and corporate governance committee then meets as a group to discuss and evaluate the qualities and skills of each candidate, both

on an individual basis and taking into account the overall composition and needs of our board of directors.

Based on the results of the evaluation process, the nominating and corporate governance committee recommends candidates for the board of directors’ approval to fill a vacancy or as director nominees for election to the board of directors by our stockholders each year in the class of directors whose term expires at the relevant annual meeting.

Science and Technology Committee

Catherine Bollard, MBChB, M.D., Scott Brun, M.D., and Shawn Tomasello, MBA, serve on the science and technology committee, which is chaired by Catherine Bollard, MBChB, M.D.

The science and technology committee supports Board oversight of the Company’s research and development, manufacturing and supply activities, by providing a forum for review of strategic considerations and issues in such areas, as well as to evaluate relevant emerging technology and advances in the field.

The science and technology committee was formed in July 2023 and held four meetings in during the fiscal year ended December 31, 2024.

Code of Business Conduct and Ethics

We have adopted a written code of business conduct and ethics that applies to our directors, officers and employees, including our principal executive officer, principal financial officer, principal accounting officer or controller, or persons performing similar functions.

A current copy of the code is posted on the corporate governance section of our website, which is located at www.cabalettabio.com/investors/corporate-governance/governance-documents .

If we make any substantive amendments to, or grant any waivers from, the code of business conduct and ethics for any officer or director, we will disclose the nature of such amendment or waiver on our website or in a current report on Form 8-K.

Insider Trading Policies and Procedures

We have adopted an insider trading policy that governs the purchase, sale, and/or other transactions of our securities by our directors, officers, employees and designated consultants that we believe is reasonably designed to promote compliance with applicable insider trading laws, rules and regulations, and listing standards applicable to us.

A copy of our insider trading policy is filed as Exhibit 19.1 to this Annual Report on Form 10-K for the fiscal year ended December 31, 2024.

In addition, with regard to trading in our own securities, it is our policy to comply with the federal securities laws and the applicable exchange listing requirements.

Our insider trading policy prohibits our directors, officers, employees and certain designated consultants, and their affiliated persons, from trading in company securities while in possession of material nonpublic information about our company.

The policy also prohibits tipping (i.e., disclosing material nonpublic information about our company to others who may trade of the basis of that information).

Under our insider trading policy, designated insiders may only trade in company securities at a time when they do not possess material nonpublic information about our company.

We also require our directors, officers and certain other employees to receive approval before trading in company securities.

Our insider trading policy also expressly prohibits short sales;

purchases or sales of puts, calls, or other derivative securities or hedging transactions;

using company securities as collateral in a margin account;

or pledging company securities as collateral for a loan.

Any waiver of the provisions of this policy requires the approval of our Audit Committee.

To date, no such requests have been made or approved.

We have also adopted an additional policy that governs adoption, modification and termination of written securities trading plans, known as Rule 10b5-1 plans, by our directors, executive officers and certain other persons.

Our policy provides that all Rule 10b5-1 plans must comply with SEC rules applicable to the Rule 10b5-1 safe harbor and imposes additional requirements and limitations.

Executiv e Compensation.

The information required by this Item 11 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2024 Annual Meeting of Stockholders within 120 days after the end of the fiscal year ended December 31, 2023 and is incorporated herein by reference.

Our named executive officers for the year ended December 31, 2024 are:

• Steven Nichtberger, M.D., our President and Chief Executive Officer;

• Gwendolyn Binder, Ph.D., our President, Science and Technology;

Chang, M.D., M.P.H., our Chief Medical Officer.

2024 Summary Compensation Table

The following table presents the compensation awarded to, earned by or paid to each of our named executive officers for the years indicated.

Nichtberger also serves as a member of our board of directors but does not receive any additional compensation for his service as a director.

Option Awards

Incentive Plan

Steven Nichtberger, M.D.

President and Chief Executive Officer

Binder, Ph.D.

President, Science and Technology

Chang, M.D., M.P.H.

Chief Medical Officer

(1) Amounts reflect the grant date fair value of option awards granted in 2024 and 2023 in accordance with the Financial Accounting Standards Board’s Accounting Standards Codification Topic 718, or ASC 718.

Such grant date fair value does not take into account any estimated forfeitures related to service-vesting conditions.

For information regarding assumptions underlying the valuation of equity awards, see Note 10 to our financial statements for the year ended December 31, 2024.

These amounts do not correspond to the actual value that may be recognized by the named executive officers upon vesting of applicable awards.

(2) The amounts represent bonuses earned in 2024 and 2023 and paid in 2025 and 2024, respectively, pursuant to the Company’s cash incentive plan based on the factors described under “Non-Equity Incentive Plan Compensation” below.

(3) Amount includes reimbursements for life insurance premiums.

Narrative to 2024 Summary Compensation Table

Our board of directors and compensation committee review compensation annually for our chief executive officer and his direct reports.

In setting executive base salaries and bonuses, and granting equity incentive awards, our board of directors considers compensation for comparable positions in the market, the historical compensation levels of our executives, individual performance as compared to our expectations and objectives, our desire to motivate our employees to achieve short-and long-term results that are in the best interests of our stockholders, and a long-term commitment to our company.

We target a general competitive position, based on independent third-party benchmark analytics to inform the mix of compensation of base salary, bonus or long-term incentives.

Our board of directors has historically determined our executives’ compensation.

Our compensation committee typically reviews and discusses management’s proposed compensation with the chief executive officer for all of his direct reports.

Based on those discussions and its discretion, taking into account the factors noted above, the compensation committee determines the compensation for each executive officer other than the chief executive officer.

Our board of directors discusses the compensation committee’s recommendations and ultimately approves the compensation of our chief executive officer without the chief executive officer and chief financial officer present.

In 2024, the compensation committee continued to retain the services of Radford, an AON Hewitt company, as its external compensation consultant and the board of directors and the compensation committee considered Radford’s input on certain compensation matters as they deemed appropriate.

Annual base salary

Each named executive officer’s base salary is a fixed component of annual compensation for performing specific duties and functions, and has been established by our board of directors taking into account each individual’s role, responsibilities, skills, and

Base salaries for our named executive officers are reviewed annually by our compensation committee, typically in connection with our annual performance review process, and adjusted from time to time, based on the recommendation of the compensation committee, to realign salaries with market levels after taking into account individual responsibilities, performance, and experience.

The base salary of each named executive officer in 2024 is noted below:

2024 Base Salary through

February 29, 2024

Base Salary Effective

March 1, 2024

Steven Nichtberger, M.D.

Binder, Ph.D.

Chang, M.D., M.P.H.

Non-Equity Incentive Plan Compensation

Annual cash awards are determined based on company performance, which is assessed based on predetermined annual objectives, and on individual performance.

When determining the individual component of our annual incentive awards, the compensation committee considers each executive’s contributions to the company’s strategic achievements and financial and operational performance.

In addition, the compensation committee considers how each executive demonstrates Cabaletta behaviors.

Each of our named executive officers was eligible to receive a bonus with respect to 2024 as a percentage of base salary listed below, modified by company and individual performance.

2024 Target Bonus Rate

(% of base salary)

Steven Nichtberger, M.D.

Binder, Ph.D.

Chang, M.D., M.P.H.

Company performance was assessed as achievement of 2024 company objectives, including certain clinical development, business development and financial and operational goals and development of a strong team culture.

As a result, the compensation committee recommended and our board of directors approved 2024 company achievement at 108%.

The compensation committee recommended (and/or approved) and the board of directors approved (as applicable, in the instance of the chief executive officer), a further adjustment of bonuses based on the individual achievement of each of the named executive officers, as noted below:

Achievement (%)

Steven Nichtberger, M.D.

Binder, Ph.D.

Chang, M.D., M.P.H.

Long-term equity incentives

Our equity grant program is intended to align the interests of our named executive officers with those of our stockholders and to motivate them to make important contributions to our performance.

In 2024, we granted stock options to each of our named executive officers, as reflected in the “Outstanding Equity Awards at 2024 Fiscal Year End Table” below.

Employment arrangements with our named executive officers

In October 2019, we entered into amended and restated employment agreements with each of our named executive officers.

Each of our named executive officers is employed at will.

Steven Nichtberger, M.D.

Under his amended and restated employment agreement, Dr.

Nichtberger is entitled to an annual base salary, which is subject to review and redetermination by our board of directors or our compensation committee, and he is eligible to receive an annual bonus determined by our board of directors or the compensation committee (subject to the terms of any applicable incentive compensation plan that may be in effect from time to time), with a target amount calculated as a percentage of his annual base salary.

Nichtberger is also eligible to participate in the employee benefit plans available to our employees, subject to the terms of those plans, and is reimbursed for his existing, personal life insurance policy premiums.

Nichtberger’s employment agreement provides that, in the event that his employment is terminated by us without “cause” or by him for “good reason,” then subject to the execution and effectiveness of a separation agreement and release and compliance with his continuing obligations, he will be entitled to receive (i) an amount equal to (x) 12 months of base salary payable on our normal payroll cycle if such termination occurs outside of the period commencing 60 days before and ending 12 months after the occurrence of the first event constituting a “change in control”, or the Change in Control Period, or (y) 1.5 times the sum of his base salary plus his target bonus for the then-current year payable on our or our successor’s normal payroll cycle over 18 months if such termination occurs within Change in Control Period;

(ii) payment of the monthly employer COBRA premium for the same level of group health coverage as in effect for Dr.

Nichtberger on the date of termination for up to (x) 12 months if such termination occurs outside of the Change in Control Period, and (y) 18 months if such termination occurs within the Change in Control Period;

and (iii) full acceleration of all stock options and other stock-based awards held by Dr.

Nichtberger if such termination occurs within the Change in Control Period.

In addition to standard good reason triggers, Dr.

Nichtberger may elect to resign for good reason if within six months following the appointment of a chairperson of the board of directors, Dr.

Nichtberger provides written notice of his reasonable dissatisfaction with such chairperson and the board fails to designate a new chairperson within 30 days of such notice.

In the event of such a resignation for good reason outside of the Change in Control Period, subject to the execution and effectiveness of a separation agreement and release and compliance with his continuing obligations, in addition to the severance benefits described above, all stock options and other stock-based awards held by Dr.

Nichtberger will accelerate and become fully exercisable or nonforfeitable.

The payments and benefits provided to Dr.

Nichtberger under his employment agreement in connection with a sale event may not be eligible for a federal income tax deduction for the company pursuant to Section 280G of the Code.

These payments and benefits also may be subject to an excise tax under Section 4999 of the Code.

If the payments or benefits payable to Dr.

Nichtberger in connection with a sale event would be subject to the excise tax on golden parachutes imposed under Section 4999 of the Code, then those payments or benefits will be reduced if such reduction would result in a higher net after tax benefit to Dr.

In addition, Dr.

Nichtberger has entered into a non-competition, non-solicitation, confidentiality and assignment agreement with us that contains, among other things, non-competition and non-solicitation provisions that apply during the term of Dr.

Nichtberger’s employment and for 12 months thereafter.

Binder, Ph.D.

Under her amended and restated employment agreement, Dr.

Binder is entitled to an annual base salary, which is subject to review and redetermination by our board of directors or our compensation committee, and she is eligible to earn an annual bonus with a target amount calculated as a percentage of her base salary.

Binder is also eligible to participate in the employee benefit plans available to our employees, subject to the terms of those plans.

Binder’s employment agreement provides that, in the event that her employment is terminated by us without “cause” or by her for “good reason,” then subject to the execution and effectiveness of a separation agreement and release and compliance with her continuing obligations, she will be entitled to receive (i) an amount equal to (x) nine months of base salary payable on our normal payroll cycle if such termination occurs outside of the Change in Control Period or (y) a lump sum in cash in the amount of 1.0 times the sum of her base salary plus her target bonus for the then-current year payable on our or our successor’s normal payroll cycle over 12 months if such termination is occurs within the Change in Control Period;

(ii) payment of the monthly employer COBRA premium for the same level of group health coverage as in effect for Dr.

Binder on the date of termination up to (x) nine months if such termination occurs outside of the Change in Control Period, and (y) 12 months if such termination occurs within the Change in Control Period;

and (iii) full acceleration of all stock options and other stock-based awards subject to time-based vesting held by Dr.

Binder if such termination occurs within the Change in Control Period.

The payments and benefits provided to Dr.

Binder under her employment agreement in connection with a sale event may not be eligible for a federal income tax deduction for the company pursuant to Section 280G of the Code.

These payments and benefits also may be subject to an excise tax under Section 4999 of the Code.

If the payments or benefits payable to Dr.

Binder in connection with a sale event would be subject to the excise tax on golden parachutes imposed under Section 4999 of the Code, then those payments or benefits will be reduced if such reduction would result in a higher net after-tax benefit to such officer.

In addition, Dr.

Binder has entered into a non-competition, non-solicitation, confidentiality and assignment agreement with us that contains, among other things, non-competition and non-solicitation provisions that apply during the term of Dr.

Binder’s employment and for 12 months thereafter.

Chang, M.D., M.P.H.

Under his amended and restated employment agreement, Dr.

Chang is entitled to an annual base salary, which is subject to review and redetermination by our board of directors or our compensation committee, and he is eligible to earn an annual bonus with a target amount calculated as a percentage of his base salary.

Chang is also eligible to participate in the employee benefit plans available to our employees, subject to the terms of those plans.

Chang’s employment agreement provides that, in the event that his employment is terminated by us without “cause” or by him for “good reason,” then subject to the execution and effectiveness of a separation agreement and release and compliance with his continuing obligations, he will be entitled to receive (i) an amount equal to (x) nine months of base salary payable on our normal payroll cycle if such termination occurs outside of the Change in Control Period or (y) a lump sum in cash in the amount of 1.0 times the sum of his base salary plus his target bonus for the then-current year payable on our or our successor’s normal payroll cycle over 12 months if such termination occurs within the Change in Control Period;

(ii) payment of the monthly employer COBRA premium for the same level of group health coverage as in effect for Dr.

Chang on the date of termination up to (x) nine months if such termination occurs outside of the Change in Control Period, and (y) 12 months if such termination occurs outside of the Change in Control Period;

and (iii) full acceleration of all stock options and other stock-based awards subject to time-based vesting held by Dr.

Chang if such termination occurs within the Change in Control Period.

The payments and benefits provided to Dr.

Chang under his employment agreement in connection with a sale event may not be eligible for a federal income tax deduction for the company pursuant to Section 280G of the Code.

These payments and benefits also may be subject to an excise tax under Section 4999 of the Code.

If the payments or benefits payable to Dr.

Chang in connection with a sale event would be subject to the excise tax on golden parachutes imposed under Section 4999 of the Code, then those payments or benefits will be reduced if such reduction would result in a higher net after-tax benefit to such officer.

In addition, Dr.

Chang has entered into a non-competition, non-solicitation, confidentiality and assignment agreement with us that contains, among other things, non-competition and non-solicitation provisions that apply during the term of Dr.

Chang’s employment and for 12 months thereafter.

Outstanding Equity Awards at 2024 Fiscal Year End Table

The following table presents information regarding all outstanding stock awards and stock options held by each of our named executive officers as of December 31, 2024.

Option awards

Number of Securities Underlying Unexercised Options (#) Exercisable

Number of Securities Underlying Unexercised Options (#) Unexercisable

Option Exercise Price ($)

Option Expiration Date

Number of Shares or Units of Stock that Have Not Vested (#)

Market Value of Shares or Units of Stock that Have Not Vested ($)

Steven Nichtberger, M.D.

Binder, Ph.D.

Chang, M.D., M.P.H.

(1) These options vest over four years, with 25% vesting on October 11, 2019, and the remaining shares vesting in 36 equal monthly installments thereafter, subject to a continued service relationship with us.

(2) These options vest over four years, with 25% vesting on October 24, 2020, and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

(3) These options vest over four years, with 25% vesting on March 1, 2021, and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

(4) These options vest over four years, with 25% vesting on October 11, 2019 and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

(5) These options vest over four years, with 25% vesting on August 22, 2020, and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

(6) These options vest over four years, with 25% vesting on June 17, 2020, and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

(7) These options vest over four years, with 25% vesting on March 1, 2022, and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

(8) These options vest over four years, with 25% vesting on January 18, 2023, and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

(9) These options vest over four years, with 25% vesting on January 18, 2024, and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

(10) These options vest over four years, with 25% vesting on March 1, 2025, and the remaining shares vesting in 12 equal quarterly installments thereafter, subject to a continued service relationship with us.

Additional Narrative Disclosure

401(k) Savings Plan.

We participate in a retirement savings plan, or 401(k) plan, that is intended to qualify for favorable tax treatment under Section 401(a) of the Code, and contains a cash or deferred feature that is intended to meet the requirements of Section 401(k) of the Code.

employees who are at least 21 years of age are generally eligible to participate in the 401(k) plan, subject to certain criteria.

Participants may make pre-tax and certain after-tax (Roth) salary deferral contributions to the plan from their eligible earnings up to the statutorily prescribed annual limit under the Code.

Participants who are 50 years of age or older may contribute additional amounts based on the statutory limits for catch-up contributions.

Participant contributions are held in trust as required by law.

An employee’s interest in his or her salary deferral contributions is 100% vested when contributed.

We have the ability to make discretionary contributions under the plan and all eligible employees will receive a Safe Harbor matching contribution up to 4% of eligible pay for the 2024 plan year.

Health and Welfare Benefits .

All of our full-time employees, including our executive officers are eligible to participate in certain medical, disability and life insurance benefit programs offered by us.

We pay the premiums for term life insurance and long-term disability for all of our employees, including our executive officers.

We also provide all employees, including executive officers, with a flexible spending account plan and paid time off benefits including, vacation, sick time and holidays.

We do not sponsor any qualified or non-qualified defined benefit plans for any of our employees or executives.

Compensation Risk Assessment

We believe that although a portion of the compensation provided to our executive officers and other employees is performance-based, our executive compensation program does not encourage excessive or unnecessary risk taking.

Our compensation programs are designed to encourage our executive officers and other employees to remain focused on both short-term and long-term strategic goals, in particular in connection with our pay-for-performance compensation philosophy.

As a result, we do not believe that our compensation programs are reasonably likely to have a material adverse effect on us.

Policy on Trading, Pledging and Hedging of Company Stock

Certain transactions in our securities (such as purchases and sales of publicly traded put and call options, and short sales) create a heightened compliance risk or could create the appearance of misalignment between management and stockholders.

In addition, securities held in a margin account or pledged as collateral may be sold without consent if the owner fails to meet a margin call or defaults on the loan, thus creating the risk that a sale may occur at a time when an officer or director is aware of material, non-public information or otherwise is not permitted to trade in Company securities.

Our insider trading policy expressly prohibits short sales and derivative transactions of our stock by our executive officers, directors, employees and certain designated consultants and contractors, including short sales of our securities.

Our insider trading policy expressly prohibits, without the advance approval of our audit committee, purchases or sales of puts, calls, or other derivative securities of the company or any derivative securities that provide the economic equivalent of ownership.

Compensation Recovery Policy (Clawback Policy)

On September 12, 2023, we adopted a Compensation Recovery Policy, or the Clawback Policy, in compliance with the requirements of the Dodd-Frank Act, final SEC rules and applicable Nasdaq listing standards (the “final clawback rules”), which covers our current and former executive officers, including all of our named executive officers.

Under the Clawback Policy, in the event that we are required to prepare a restatement of our previously issued financial statements due to our material noncompliance with any financial reporting requirement under securities laws, we are required to recover (subject to certain limited exceptions described in the Clawback Policy and permitted under the final clawback rules) any cash or equity incentive-based compensation received by any current or former executive officer after the effective date of the Clawback Policy and in the three years prior to the date we are required to restate our financial statements that is in excess of the amount that would have been received based on the restated financial statements.

Compensation Committee Interlocks and Insider Participation

Each of Richard Henriques, Mark Simon and Shawn Tomasello, served on the compensation committee during fiscal year 2024.

No member of the compensation committee has ever been an officer or employee of the Company.

None of our executive officers serve, or have served during the last fiscal year, as a member of the board of directors, compensation committee, or other

board committee performing equivalent functions of any other entity that has one or more executive officers serving as one of our directors or on our compensation committee.

Policy on the Timing of Awards of Options and Other Option-Like Instruments

Our compensation committee has generally granted annual equity awards, including stock option grants to our named executive officers, in the first quarter of each fiscal year, specifically early March.

In addition, new hires receive stock option grants at the time of their hiring.

Eligible employees, including our named executive officers, may voluntarily enroll in our Employee Stock Purchase Plan and receive an option to purchase shares at a discount using payroll deductions accumulated during the prior six months, with purchase dates occurring in May and November.

During 2024, our compensation committee did not take into account any material nonpublic information when determining the timing and terms of equity incentive awards, and we did not time the disclosure of material nonpublic information for the purpose of affecting the value of executive compensation.

During 2024, we did not grant stock options to our named executive officers during any period beginning four business days before and ending one business day after the filing or furnishing of a Form 10-Q, 10-K or 8-K that discloses material nonpublic information.

Please see Item 10 for details regarding corporate governance, including the composition of our compensation committee, as required by Regulation S-K 407(e)(4) and (e)(5).

Director Compensation

The following table presents the total compensation for each person who served as a non-employee member of our board of directors and received compensation for such service during the fiscal year ended December 31, 2024.

Other than as set forth in the table and described more fully below, we did not pay any compensation, make any equity awards or non-equity awards to, or pay any other compensation to any of the non-employee members of our board of directors in 2024.

We reimburse members of our board of directors for reasonable travel expenses.

Nichtberger, our Chief Executive Officer and President, did not receive any compensation for his service as a member and Chairman of our board of directors in 2024.

Nichtberger’s compensation for service as an employee for fiscal years 2024 and 2023 is presented in “Executive Compensation—2024 Summary Compensation Table.”

Fees Earned or

Paid In Cash ($)

Option Awards (1)(2)

All Other Compensation

Catherine Bollard, MBChB, M.D.

Scott Brun, M.D.

Richard Henriques, MBA

Mark Simon, MBA

Shawn Tomasello, MBA

(1) Amount shown reflects the grant date fair value of an option award granted during 2024.

The grant date fair value was computed in accordance with Financial Accounting Standards Board Accounting Standards Codification Topic 718, Compensation—Stock Compensation, or FASB ASC Topic 718, disregarding the effect of estimated forfeitures related to service-based vesting.

See Note 10 to the financial statements in our 2024 Annual Report on Form 10-K regarding assumptions we made in determining the fair value of option awards.

(2) As of December 31, 2024, the aggregate number of shares subject to option awards held by our non-employee directors were:

134,428 and Ms.

Tomasello 66,000.

As of December 31, 2024, the aggregate number of unvested shares outstanding held by our non-employee directors were:

22,000 and Ms.

Tomasello 47,667.

Amended and Restated Non-Employee Director Compensation Policy

Under our director compensation policy, we pay our non-employee directors a cash retainer for service on the board of directors and for service on each committee on which the director is a member.

The chairman of each committee receives a higher retainer for such service.

These fees are payable in arrears in four equal quarterly installments on the last day of each quarter, provided that the amount of such payment is prorated for any portion of such quarter that the director is not serving on our board of directors.

The fees paid to non-employee directors for service on the board of directors and for service on each committee of the board of directors on which the director is a member for 2024 are as follows:

Member Annual

Chairperson Annual

Board of Directors

Audit Committee

Compensation Committee

Nominating and Corporate Governance Committee

Science and Technology Committee

In February 2025, we amended our director compensation policy.

Accordingly, the fees paid to non-employee directors for service on the board of directors and for service on each committee of the board of directors on which the director is a member for 2025 are as follows:

Member Annual

Chairperson Annual

Board of Directors

Audit Committee

Compensation Committee

Nominating and Corporate Governance Committee

Science and Technology Committee

We also reimburse our non-employee directors for reasonable out-of-pocket expenses incurred in connection with attending our board of director and committee meetings.

In addition, each new non-employee director elected to our board of directors will be granted an initial, one-time award of a stock option to purchase 44,000 shares, which shall vest in equal quarterly installments over a three-year period from the date of vesting commencement, subject to continued service as a director through each such vesting date.

In addition, on the date of each annual meeting of stockholders of our company, each non-employee director will receive an annual stock option award of 22,000 shares, which shall vest in full upon the earlier to occur of the first anniversary of the date of grant or the date of the next annual meeting provided , however , that all vesting shall cease if the director resigns from the board of directors or otherwise ceases to serve as a director, unless the board of directors determines that the circumstances warrant continuation of vesting.

This program is intended to provide a total compensation package that enables us to attract and retain qualified and experienced individuals to serve as directors and to align our directors’ interests with those of our stockholders.

Security Ownership of Certain Beneficial Own ers and Management and Related Stockholder Matters.

The information required by this Item 12 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2024 Annual Meeting of Stockholders within 120 days after the end of the fiscal year ended December 31, 2023 and is incorporated herein by reference.

Equity Compensation Plan Information

The following table provides information as of December 31, 2024 regarding shares of common stock that may be issued under our equity compensation plans, consisting of the 2018 Plan, the 2019 Plan and the 2019 Employee Stock Purchase Plan, or the ESPP.

We have no equity compensation plans that were not approved by security holders.

Plan Category

Number of securities

to be issued upon

exercise of outstanding

options, units and rights (#)

Weighted-average

exercise price of

outstanding options,

units and rights ($)

Number of securities

remaining available for

future issuance under

equity compensation plan

(excluding securities

referenced in first column)

Equity compensation plans approved by security holders(1)

11,231,148(2)

1,693,564(3)(4)

Equity compensation plans not approved by security holders

(1) Consists of our 2019 Stock Option and Incentive Plan, 2018 Stock Option and Grant Plan, and 2019 Employee Stock Purchase Plan.

Following our initial public offering, we have not and will not grant any awards under our 2018 Stock Option and Grant Plan, but all outstanding awards under the 2018 Stock Option and Grant Plan will continue to be governed by their existing terms.

The shares of common stock underlying any awards granted under the 2018 Stock Option and Grant Plan or 2019 Stock Option and Incentive Plan that are forfeited, canceled, reacquired by us prior to vesting, satisfied without the issuance of stock, or otherwise terminated (other than by exercise) and the shares of common stock that are withheld upon exercise of a stock option or settlement of such award to cover the exercise price or tax withholding will be added to the shares of common stock available for issuance under the 2019 Stock Option and Incentive Plan.

(2) Includes 11,231,148 shares of common stock issuable upon the exercise of outstanding options, of which 1,235,458 are subject to our 2018 Stock Option and Grant Plan and 9,995,690 are subject to our 2019 Stock Option and Incentive Plan.

(3) As of December 31, 2024, there were 1,379,305 shares available for grant under the 2019 Stock Option and Incentive Plan and 314,259 shares available for grants under the 2019 Employee Stock Purchase Plan.

(4) The 2019 Stock Option and Incentive Plan provides that the number of shares reserved and available for issuance under the plan will automatically increase each January 1, beginning on January 1, 2020, by 4% of the outstanding number of shares of our common stock on the immediately preceding December 31.

The 2019 Employee Stock Purchase Plan provides that the number of shares reserved and available for issuance will automatically increase each January 1, beginning on January 1, 2020, through January 1, 2029, by the least of 234,229 shares of our common stock, 1% of the outstanding number of shares of our common stock on the immediately preceding December 31, or such lesser number of shares as determined by our compensation committee.

Security Ownership of Certain Beneficial Owners and Management

The following table sets forth information, to the extent known by us or ascertainable from public filings, with respect to the beneficial ownership of our common stock as of March 7, 2025 by:

• each of our directors;

• each of our named executive officers;

• all of our directors and executive officers as a group;

• each person, or group of affiliated persons, who is known by us to beneficially own greater-than-5.0% of our common stock.

The column entitled “Shares Beneficially Owned” is based on a total of 50,743,101 shares of our common stock outstanding as of March 7, 2025.

Beneficial ownership is determined in accordance with the rules and regulations of the SEC and includes voting or investment power with respect to our common stock.

Shares of our common stock subject to options or warrants that are currently exercisable or exercisable within 60 days of March 7, 2025 are considered outstanding and beneficially owned by the person holding the options or warrants for the purpose of calculating the percentage ownership of that person but not for the purpose of calculating the percentage ownership of any other person.

Except as otherwise noted, the persons and entities in this table have sole voting and investing power with respect to all of the shares of our common stock beneficially owned by them, subject to community property

laws, where applicable.

Except as otherwise indicated in the table below, addresses of named beneficial owners are in care of Cabaletta Bio, Inc., 2929 Arch Street, Suite 600, Philadelphia, Pennsylvania 19104.

Shares beneficially owned

Name and address of beneficial owner(1)

> 5% Stockholders:

BlackRock, Inc.(2)

Entities Affiliated with Adage Capital Partners, L.P.(3)

Rowe Price Investment Management, Inc.(4)

Entities affiliated with Prudential Financial, Inc.(5)

Bain Capital Life Sciences Opportunities III, LP(6)

The Vanguard Group(7)

Named Executive Officers and Directors:

Steven Nichtberger, M.D.(8)

Binder, Ph.D.(9)

David Chang, M.D., M.P.H.(10)

Catherine Bollard, MBChB, M.D.(11)

Scott Brun, M.D.(12)

Richard Henriques, MBA(13)

Mark Simon, MBA(14)

Shawn Tomasello, MBA(15)

All executive officers and directors as a group (11 persons)(15)

* Represents beneficial ownership of less than one percent.

(1) Unless otherwise indicated, the address for each beneficial owner is c/o Cabaletta Bio, Inc., 2929 Arch Street, Suite 600, Philadelphia, Pennsylvania 19104.

(2) The information reported is based on information in a Schedule 13G/A, as filed by BlackRock, Inc.

with the SEC on February 5, 2025.

In that filing, BlackRock, Inc.

reports sole voting power with respect to 3,329,097 shares of common stock and sole dispositive power with respect to 3,397,260 shares, and lists its address as 50 Hudson Yards, New York, New York 10001.

(3) The information is based on a Schedule 13G/A filed with the SEC on November 12, 2024.

Consists of 3,036,645 shares of common stock and 597,830 shares of common stock issuable upon the exercise of pre-funded warrants held by Adage Capital Partners, L.P., or ACP.

Adage Capital Partners GP, L.L.C., or ACPGP, is the general partner of ACP.

Adage Capital Management, L.P., or ACM, is the investment manager of ACP.

Adage Capital Advisors, L.L.C., or ACA, is managing member of ACPGP.

Adage Capital Partners LLC, or ACPLLC , is the general partner of ACM, with respect to the shares of voting common stock directly held by ACP.

Robert Atchinson and Phillip Gross are managing members of ACA and ACPGP and are general partners of ACP.

Each of ACP, ACPGP, ACA, ACM, Robert Atchinson, and Phillip Gross have shared voting and dispositive power over all of the shares.

The ability of the Adage entities to exercise their pre-funded warrants is subject to a beneficial ownership limitation, which prevents the Adage entities from exercising any portion of the warrants to the extent such exercise would result in the Adage entities exceeding a certain percentage of the total number of issued and outstanding shares of our common stock following such exercise.

The address for Adage Capital Partners, L.P.

is 200 Clarendon Street, 52nd Floor, Boston, Massachusetts 02116.

(4) The information reported is based on information in a Schedule 13G/A, as filed by T.

Rowe Price Investment Management, Inc.

(Price Investment Management) with the SEC on November 14, 2024.

In that filing, T.

Rowe Price Investment Management, Inc.

(Price Investment Management) reports sole voting power with respect to 3,666,024 shares of common stock and sole dispositive power with respect to 3,673,724 shares, and lists its address as 101 E.

Pratt Street, Baltimore, MD 21201.

(5) The information reported is based on information in a Schedule 13G/A, as filed by Prudential Financial, Inc.

with the SEC on December 5, 2024.

In that filing, Prudential Financial, Inc.

reports shared voting and dispositive power over (i) 2,796,053 shares of our common stock, being 2,512,053 shares held through its subsidiary Jennison Associates LLC and 284,000 shares held through its subsidiary PGIM, Inc., and (ii) sole voting and dispositive power over 2,810 shares of our common stock held through its subsidiary PGIM Quantitative Solutions LLC.

The address provided for Prudential Financial, Inc.

is 751 Broad Street, New Jersey 07102.

(6) The information reported is based on information in a Schedule 13G, as filed by Bain Capital Life Sciences Opportunities III, LP with the SEC on August 22, 2024.

In that filing, Bain Capital Life Sciences Opportunities III, LP reports shared voting power and shared dispositive power with respect to 2,760,888 shares of common stock.

Bain Capital Life Sciences Investors, LLC, or BCLSI, is the manager of Bain Capital Life Sciences III General Partner, LLC, which is the general partner of Bain Capital Life Sciences Fund III, L.P., which is the sole member of Bain Capital Life Sciences Opportunities III GP, LLC, which is the general partner of Bain Capital Life Sciences Opportunities III, LP.

As a result, BCLSI may be deemed to share voting and dispositive power with respect to the securities held by Bain Capital Life Sciences Opportunities III, LP.

The address of BCLSI is 200 Clarendon Street, Boston, MA 02116.

(7) The information reported is based on information in a Schedule 13G/A, as filed by The Vanguard Group with the SEC on November 12, 2024.

In that filing, The Vanguard Group reports shared voting power with respect to 31,135 shares of common stock, sole dispositive power with respect to 2,500,994 shares and shared dispositive power with respect to 52,716 shares, and lists its address as 100 Vanguard Blvd., Malvern, PA 19355.

(8) Consists of (i) 986,483 shares of common stock held by Dr.

Nichtberger, (ii) 363,000 shares of common stock held by the 2017 Nichtberger Family Trust, or the Trust Shares, and (iii) 1,177,867 shares of common stock underlying options exercisable within 60 days of March 7, 2025.

Nichtberger may be deemed to beneficially own the Trust Shares.

Nichtberger disclaims beneficial ownership of the Trust Shares and this shall not be deemed an admission that he is the beneficial owner of the Trust Shares.

(9) Consists of (i) 20,000 shares of common stock held and (ii) 583,831shares of common stock underlying options exercisable within 60 days of March 7, 2025.

(10) Consists of 612,846 shares of common stock underlying options exercisable within 60 days of March 7, 2025.

(11) Consists of (i) 1,000 shares of common stock held and (ii) 112,428 shares of common stock underlying options exercisable within 60 days of March 7, 2025.

(12) Consists of 88,000 shares of common stock underlying options exercisable within 60 days of March 7, 2025.

(13) Consists of 112,428 shares of common stock underlying options exercisable within 60 days of March 7, 2025.

(14) Consists of (i) 143,144 shares of common stock held and (ii) 112,428 shares of common stock underlying options exercisable within 60 days of March 7, 2025.

(15) Consists of 25,667 shares of common stock underlying options exercisable within 60 days of March 7, 2025.

(16) See notes (7) through (14);

also includes an aggregate of (i) 50,000 shares of common stock and (ii) 1,066,947 shares of common stock subject to options exercisable within 60 days of March 7, 2025 held by Anup Marda, our Chief Financial Officer, Michael Gerard, our General Counsel and Secretary, and Arun Das, M.D., our Chief Business Officer.

Certain Relationships and Related Transactions, and Director Independence.

The information required by this Item 13 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2024 Annual Meeting of Stockholders within 120 days after the end of the fiscal year ended December 31, 2023 and is incorporated herein by reference.

Principal Accoun ting Fees and Services.

The information required by this Item 14 will be included in our definitive proxy statement to be filed with the SEC with respect to our 2024 Annual Meeting of Stockholders within 120 days after the end of the fiscal year ended December 31, 2023 and is incorporated herein by reference.

Certain Relationships and Transactions

Other than the compensation agreements and other arrangements described under “Executive compensation” and “Director compensation” in this Annual Report on Form 10-K for the fiscal year ended December 31, 2024 and the transactions described below, since January 1, 2023, there has not been and there is not currently proposed, any transaction or series of similar transactions to which we were, or will be, a party in which the amount involved exceeded, or will exceed, $120,000 (or, if less, 1% of the average of our total assets amounts at December 31, 2023 and 2024) and in which any director, executive officer, holder of five percent or more of any class of our capital stock or any member of the immediate family of, or entities affiliated with, any of the foregoing persons, had, or will have, a direct or indirect material interest.

May 2023 Offering

In May 2023, we issued 8,337,500 shares of our common stock at a price of $12.00 per share in connection with an underwritten public offering.

Certain existing holders of five percent or more of a class of our capital stock participated in the transaction, as evidenced by the table below.

Greater than Five Percent Holder

Aggregate Common Stock Purchased

Purchase Price

Adage Capital Partners LP

Fred Alger Management Inc

Cormorant Global Healthcare Master Fund LP

Commodore Capital LP

Limitation of Liability and Indemnification of Officers and Directors

Our certificate of incorporation contains provisions that limit the liability of our directors for monetary damages to the fullest extent permitted by Delaware law.

Consequently, our directors will not be personally liable to us or our stockholders for monetary damages for any breach of fiduciary duties as directors, except liability for the following:

• any breach of their duty of loyalty to our company or our stockholders;

• any act or omission not in good faith or that involves intentional misconduct or a knowing violation of law;

• unlawful payments of dividends or unlawful stock repurchases or redemptions as provided in Section 174 of the Delaware General Corporation Law;

• any transaction from which they derived an improper personal benefit.

Any amendment to, or repeal of, these provisions will not eliminate or reduce the effect of these provisions in respect of any act, omission or claim that occurred or arose prior to that amendment or repeal.

If the Delaware General Corporation Law is amended to provide for further limitations on the personal liability of directors of corporations, then the personal liability of our directors will be further limited to the greatest extent permitted by the Delaware General Corporation Law.

In addition, we adopted bylaws which provide that we will indemnify, to the fullest extent permitted by law, any person who is or was a party or is threatened to be made a party to any action, suit or proceeding by reason of the fact that he or she is or was one of our directors or officers or is or was serving at our request as a director or officer of another corporation, partnership, joint venture, trust, or other enterprise.

Our bylaws provide that we may indemnify to the fullest extent permitted by law any person who is or was a party or is threatened to be made a party to any action, suit, or proceeding by reason of the fact that he or she is or was one of our employees or agents or is or was serving at our request as an employee or agent of another corporation, partnership, joint venture, trust or other enterprise.

Our bylaws also provide that we must advance expenses incurred by or on behalf of a director or officer in advance of the final disposition of any action or proceeding, subject to very limited exceptions.

We have entered into and in the future plan to enter into agreements to indemnify our directors and executive officers.

These agreements, among other things, require us to indemnify these individuals for certain expenses (including attorneys’ fees), judgments, fines and settlement amounts reasonably incurred by such person in any action or proceeding, including any action by or in our right, on account of any services undertaken by such person on behalf of our company or that person’s status as a member of our board of directors to the maximum extent allowed under Delaware law.

Related person transaction policy

Our board of directors adopted a written related person transaction policy providing that transactions with our directors, officers and holders of five percent or more of our voting securities and their affiliates, each a related person, must be approved by our audit committee.

This policy became effective on October 29, 2019, the date our registration statement for our initial public offering became effective.

Pursuant to this policy, the audit committee has the primary responsibility for reviewing and approving or disapproving “related person transactions,” which are transactions between us and related persons in which the aggregate amount involved exceeds or may be expected to exceed $120,000 and in which a related person has or will have a direct or indirect material interest.

For purposes of this policy, a related person is defined as a director, executive officer, nominee for director, or greater than 5% beneficial owner of our common stock, in each case since the beginning of the most recently completed year, and their immediate family members.

As appropriate for the circumstances, the audit committee will review and consider:

• the related person’s interest in the related person transaction;

• the approximate dollar amount involved in the related person transaction;

• the approximate dollar amount of the related person’s interest in the transaction without regard to the amount of any profit or loss;

• whether the transaction was undertaken in the ordinary course of our business;

• whether the terms of the transaction are no less favorable to us than terms that could have been reached with an unrelated third party;

• the purpose of, and the potential benefits to us of, the related-party transaction;

• any other information regarding the related-party transaction or the related person in the context of the proposed transaction that would be material to investors in light of the circumstances of the particular transaction.

Director Independence

Applicable Nasdaq rules require a majority of a listed company’s board of directors to be comprised of independent directors within one year of listing.

In addition, the Nasdaq rules require that, subject to specified exceptions, each member of a listed company’s audit, compensation and nominating and corporate governance committees be independent and that audit committee members also satisfy independence criteria set forth in Rule 10A-3 under the Exchange Act and that compensation committee members satisfy independence criteria set forth in Rule 10C-1 under the Exchange Act.

Under applicable Nasdaq rules, a director will only qualify as an “independent director” if, in the opinion of the listed company’s board of directors, that person does not have a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director.

In order to be considered independent for purposes of Rule 10A-3, a member of an audit committee of a listed company may not, other than in his or her capacity as a member of the audit committee, the board of directors, or any other board committee, accept, directly or indirectly, any consulting, advisory, or other compensatory fee from the listed company or any of its subsidiaries or otherwise be an affiliated person of the listed company or any of its subsidiaries.

In addition, in affirmatively determining the independence of any director who will serve on a company’s compensation committee, Rule 10C-1 under the Exchange Act requires that a company’s board of directors must consider all factors specifically relevant to determining whether a director has a relationship to such company which is material to that director’s ability to be independent from management in connection with the duties of a compensation committee member, including:

the source of compensation to the director, including any consulting, advisory or other compensatory fee paid by such company to the director, and whether the director is affiliated with the company or any of its subsidiaries or affiliates.

Our board of directors has determined that all members of the board of directors, except Dr.

Nichtberger are independent directors, including for purposes of the rules of Nasdaq and the SEC.

In making such independence determination, our board of directors considered the relationships that each non-employee director has with us and all other facts and circumstances that our board of directors deemed relevant in determining their independence, including the beneficial ownership of our capital stock by each non-employee director.

In considering the independence of the directors listed above, our board of directors considered the association of our directors with the holders of more than 5% of our common stock.

There are no family relationships among any of our directors or executive officers.

Nichtberger is not an independent director under these rules because he is an executive officer of the Company.

Principal Accountant Fees and Services.

Our independent public accounting firm is Ernst & Young, Philadelphia, PA, PCAOB Auditor ID 42 .

Exhibits, Financ ial Statement Schedules.

Cabaletta incurred the following fees from Ernst & Young for the audit of the financial statements and for other services provided during the years ended December 31, 2024 and 2023.

Audit fees(1)

Audit-Related fees(2)

All other fees(4)

(1) Audit fees consist of fees for the audit of our annual financial statements, the review of our interim financial statements included in our quarterly reports on Form 10-Q, comfort letters and consents.

(2) Audit-related fees consist of services that are reasonably related to the performance of the audit or review of our financial statements.

There were no such fees incurred in 2024 or 2023.

(3) Tax Fees consist of fees for tax compliance, advice and tax services.

(4) There were no other fees incurred in 2024 or 2023.

Audit Committee Pre-approval Policy and Procedures

Our audit committee has adopted policies and procedures relating to the approval of all audit and non-audit services that are to be performed by our independent registered public accounting firm.

This policy provides that we will not engage our independent registered public accounting firm to render audit or non-audit services unless the service is specifically approved in advance by our audit committee or the engagement is entered into pursuant to the pre-approval procedure described below.

From time to time, our audit committee may pre-approve specified types of services that are expected to be provided to us by our independent registered public accounting firm during the next 12 months.

Any such pre-approval details the particular service or type of services to be provided and is also generally subject to a maximum dollar amount.

During our 2024 and 2023 fiscal years, no services were provided to us by Ernst & Young other than in accordance with the pre-approval policies and procedures described above.

Exhibits, Consolidated Financ ial Statement Schedules.

(a) The following documents are filed as part of this Annual Report on Form 10-K:

(1) Financial Statements:

(1) Consolidated Financial Statements:

Report of Independent Registered Public Accounting Firm

Balance Sheets as of December 31, 2023 and 2022

Statements of Operations and Comprehensive Loss for the Years Ended December 31, 2023 and 2022

Statements of Stockholders’ Equity for the Years Ended December 31, 2023 and 2022

Statements of Cash Flows for the Years Ended December 31, 2023 and 2022

Notes to Financial Statements

(2) Financial Statement Schedules:

All financial statement schedules have been omitted because they are not applicable, not required or the information required is shown in the financial statements or the notes thereto.

Consolidated Balance Sheets as of December 31, 2024 and 2023

Consolidated Statements of Operations and Comprehensive Loss for the Years Ended December 31, 2024 and 2023

Consolidated Statements of Stockholders’ Equity for the Years Ended December 31, 2024 and 2023

Consolidated Statements of Cash Flows for the Years Ended December 31, 2024 and 2023

Notes to Consolidated Financial Statements

(2) Consolidated Financial Statement Schedules:

All consolidated financial statement schedules have been omitted because they are not applicable, not required or the information required is shown in the consolidated financial statements or the notes thereto.

(3) Exhibits.

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Report of Independent Registered Public Accounting Firm

Balance Sheets as of December 31, 2023 and 2022

Statements of Operations and Comprehensive Loss for the Years Ended December 31, 2023 and 2022

Statements of Stockholders’ Equity for the Years Ended December 31, 2023 and 2022

Statements of Cash Flows for the Years Ended December 31, 2023 and 2022

Notes to Financial Statements

Consolidated Balance Sheets as of December 31, 2024 and 2023

Consolidated Statements of Operations and Comprehensive Loss for the Years Ended December 31, 2024 and 2023

Consolidated Statements of Stockholders’ Equity for the Years Ended December 31, 2024 and 2023

Consolidated Statements of Cash Flows for the Years Ended December 31, 2024 and 2023

Notes to Consolidated Financial Statements

Report of Independent Regist ered Public Accounting Firm

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Opinion on the Financial Statements

We have audited the accompanying balance sheets of Cabaletta Bio, Inc.

(the Company) as of December 31, 2023 and 2022, the related statements of operations and comprehensive loss, stockholders’ equity and cash flows for the years then ended, and the related notes (collectively referred to as the “financial statements”).

In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2023 and 2022, and the results of its operations and its cash flows for the years then ended, in conformity with U.S.

We have audited the accompanying consolidated balance sheets of Cabaletta Bio, Inc.

(the Company) as of December 31, 2024 and 2023, the related consolidated statements of operations and comprehensive loss, stockholders’ equity and cash flows for each of the two years in the period ended December 31, 2024, and the related notes (collectively referred to as the “consolidated financial statements”).

In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2024 and 2023, and the results of its operations and its cash flows for each of the two years in the period ended December 31, 2024, in conformity with U.S.

generally accepted accounting principles.

The Company's Ability to Continue as a Going Concern

The accompanying consolidated financial statements have been prepared assuming that the Company will continue as a going concern.

As discussed in Note 1 to the consolidated financial statements, the Company has suffered recurring losses from operations and has stated that substantial doubt exists about the Company’s ability to continue as a going concern.

Management's evaluation of the events and conditions and management’s plans regarding these matters are also described in Note 1.

The consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty.

Basis for Opinion

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We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the financial statements that was communicated or required to be communicated to the audit committee and that:

(1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective or complex judgments.

The communication of the critical audit matter does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the account or disclosures to which it relates.

Accounting for Accrued Clinical Trial Expenses

Description of the Matter

As disclosed in Note 2 to the consolidated financial statements, the Company expenses research and development costs as incurred, which include costs relating to clinical trial activities.

The Company’s accrued clinical trial expenses are based on factors such as estimates of the work completed in accordance with agreements established with a contract research organization.

As disclosed in Note 5 to the consolidated financial statements, the Company’s total accrued expenses and other current liabilities related to research and development costs were $3.5 million at December 31, 2024, which included the estimated clinical trial expenses incurred as of December 31, 2024 but not paid as of that date.

Auditing the Company’s accrued clinical trial expenses required subjective auditor judgement due to the estimation required by management in determining the services provided but not yet invoiced.

Specifically, the amount of accrued clinical trial expenses recognized is sensitive to the availability of information to make the estimate, including the estimate of the period over which services will be performed, the associated cost of such services, and the level of services performed and progress in the period for which the Company has not yet received an invoice.

How We Addressed the Matter in Our Audit

To test the accrued clinical trial expenses our audit procedures included, among others, reviewing a sample of agreements with the service providers to corroborate key financial and contractual terms, and testing the accuracy and completeness of the underlying data used in the accrual expense computations.

We also evaluated management’s estimates of the progress of a sample of clinical trial activities by making inquiries of the Company’s operations personnel that oversee the clinical trials and confirming information directly with the contract research organization.

To evaluate the completeness of the accruals, we also examined subsequent invoices from the service providers and cash disbursements to the service providers, to the extent such invoices were received, or payments were made prior to the date that the consolidated financial statements were issued.

/s/ Ernst & Young LLP

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CABALETTA BIO, INC.

Balance Sheets

Consolidated Balance Sheets

(in thousands, except share and per share amounts)

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Property and equipment, net

Finance lease right-of-use assets

Operating lease right-of-use assets

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Accrued and other current liabilities

Finance lease liabilities, current portion

Operating lease liabilities, current portion

Total current liabilities

Finance lease liabilities, net of current portion

Operating lease liabilities, net of current portion

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Preferred stock, $ 0.00001 par value:

10,000,000 shares authorized as of December 31, 2023 and 2022;

no shares issued or outstanding at December 31, 2023 or 2022

10,000,000 shares authorized as of

December 31, 2024 and December 31, 2023;

no shares issued or

outstanding at December 31, 2024 and December 31, 2023

Voting and non-voting common stock, $ 0.00001 par value:

150,000,000 ( 143,590,481 voting and 6,409,519 non-voting) shares authorized as of December 31, 2023 and December 31, 2022;

47,823,232 ( 46,378,937 voting and 1,444,295 non-voting) shares issued and outstanding as of December 31, 2023 and 29,445,134 ( 27,584,375 voting and 1,860,759 non-voting) shares issued and outstanding as of December 31, 2022

( 143,590,481 voting and 6,409,519 non-voting) shares authorized as of

December 31, 2024 and December 31, 2023;

50,743,101 voting shares

issued and outstanding as of December 31, 2024 and 47,823,232

( 46,378,937 voting and 1,444,295 non-voting) shares issued and

outstanding as of December 31, 2023

Additional paid-in capital

Accumulated other comprehensive income (loss)

Accumulated other comprehensive income

Accumulated deficit

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Total liabilities and stockholders’ equity

The accompanying notes are an integral part of these financial statements.

The accompanying notes are an integral part of these consolidated financial statements.

CABALETTA BIO, INC.

Statements of Operations and Comprehensive Loss

Consolidated Statements of Operations and Comprehensive Loss

(in thousands, except share and per share amounts)

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Interest income

Other comprehensive income (loss):

Net unrealized income (loss) on available-for-sale investments, net of tax

Interest expense

Other comprehensive income:

Net unrealized (loss) gain on available-for-sale investments, net of tax

Net comprehensive loss

Net loss per share of voting and non-voting common stock, basic and diluted

The accompanying notes are an integral part of these financial statements.

The accompanying notes are an integral part of these consolidated financial statements.

CABALETTA BIO, INC.

Statements of Stockholders’ Equity

Consolidated Statements of Stockholders’ Equity

(in thousands, except share and per share amounts)

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Balance—December 31, 2022

Issuance of common stock and pre-funded warrants for the purchase of common stock, net of issuance costs of $ 2,438

Issuance of common stock upon exercise of pre-funded warrants

Stock-based compensation

Issuance of common stock, net of issuance costs of $ 8,647

Issuance of common stock in connection with exercise of stock options

Issuance of common stock under employee stock purchase plan

Issuance of common stock upon exercise of pre-funded warrants

Net unrealized losses on available-for-sale securities

Stock-based compensation

Balance—December 31, 2023

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Issuance of common stock upon exercise of pre-funded warrants

Net unrealized gains on available-for-sale securities

Net unrealized losses on available-for-sale securities

Balance—December 31, 2024

The accompanying notes are an integral part of these financial statements.

The accompanying notes are an integral part of these consolidated financial statements.

CABALETTA BIO, INC.

Statements of Cash Flows

Consolidated Statements of Cash Flows

(in thousands)

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Stock-based compensation

Non-cash lease expense

Accretion of lease liabilities

Gain on derecognition of embedded lease upon lease amendment

Amortization of finance lease

Non-cash operating lease expense

Accretion of operating lease liabilities

Amortization of discount on investments

Loss on foreign currency exchange rates

Changes in operating assets and liabilities:

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Proceeds from maturities of investments

Net cash used in investing activities

Net cash provided by (used in) investing activities

Cash flows from financing activities:

Proceeds from the issuance of common stock, net of issuance costs

Proceeds from issuance of common stock in connection with the exercise of stock options

Proceeds from issuance of common stock under employee stock purchase plan

Proceeds from issuance of common stock in connection with the

exercise of stock options

Proceeds from issuance of common stock under employee stock

purchase plan

Principal payments on finance leases

Net cash provided by financing activities

Net increase (decrease) in cash and cash equivalents

Effect of exchange rate changes on cash and cash equivalents

Net (decrease) increase in cash and cash equivalents

Cash and cash equivalents—beginning of period

Cash and cash equivalents—end of period

Supplemental disclosures of non-cash investing and financing activities:

Property and equipment purchases included in accounts payable

Right-of-use assets obtained in exchange for lease obligations

Derecognition of embedded lease upon lease amendment

Offering costs included in accounts payable

The accompanying notes are an integral part of these financial statements.

Supplemental disclosures

Cash paid for interest

Property and equipment purchases included in accounts payable and accrued expenses

Right-of-use assets obtained in exchange for finance lease obligations

Right-of-use assets obtained in exchange for operating lease obligations

The accompanying notes are an integral part of these consolidated financial statements.

CABALETTA BIO, INC.

Notes to the Fina ncial Statements

Notes to the Consolidated Financial Statements

(in thousands, except share and per share amounts)

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and, in August 2018, changed its name to Cabaletta Bio, Inc.

The consolidated financial statements include the accounts of Cabaletta Bio and its wholly owned subsidiaries:

Cabaletta Bio GmbH and Cabaletta Bio (Germany) GmbH.

All intercompany balances and transactions have been eliminated in consolidation.

The Company is headquartered in Philadelphia, Pennsylvania.

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As a result, the Company is unable to predict the timing or amount of increased expenses or when or if the Company will be able to achieve or maintain profitability.

Further, the Company is dependent on third parties including Penn and certain Penn-affiliated entities for certain research and development activities, including manufacturing services (Note 6 and Note 7).

Further, the Company is dependent on third parties for certain research and development activities, including manufacturing services (Note 6 and Note 7).

Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval, prior to commercialization.

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If the Company fails to become profitable or is unable to sustain profitability on a continuing basis, then it may be unable to continue its operations at planned levels and be forced to reduce its operations.

Liquidity and Going Concern

In accordance with Accounting Standards Codification (“ASC”) 205-40, Going Concern, ("ASC 205-40") the Company evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern.

The Company has sustained annual operating losses since inception and expects to continue to generate operating losses for the foreseeable future.

As of December 31, 2024, the Company has incurred an accumulated deficit of $ 349,101 and has a cash and cash equivalents balance of $ 163,962 .

The Company’s ultimate success depends on the outcome of its research and development activities.

The Company had cash and cash equivalents and investments of $ 241,249 as of December 31, 2023.

Through December 31, 2023, the Company has incurred an accumulated deficit of $ 233,237 .

Management expects to incur additional losses in the future as it continues its research and development and will need to raise additional capital to fully implement its business plan and to fund its operations.

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However, if such financing is not available at adequate levels and on a timely basis, or such agreements are not available on favorable terms, or at all, as and when needed, the Company will need to reevaluate its operating plan and may be required to delay or discontinue the development of one or more of its product candidates or operational initiatives.

The Company expects that its cash and cash equivalents and investments as of December 31, 2023 will be sufficient to fund its projected operations for at least 12 months following the date the Company files this Annual Report on Form 10-K with the Securities and Exchange Commission (SEC).

The Company expects that its current cash and cash equivalents may not be sufficient to fund operations for at least the next twelve months from the date of issuance of these consolidated financial statements.

The Company's cash forecast contains estimates and assumptions based on success of ongoing clinical trials, and management cannot predict the amount or timing of all expenditures with certainty.

Accordingly, the Company has concluded that substantial doubt exists about the Company’s ability to continue as a going concern.

The accompanying financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business.

Summary of Significant Accounting Policies

Principles of Consolidation

The accompanying consolidated financial statements included herein have been prepared in conformity with accounting principles generally accepted in the United States ("GAAP") and under the rules and regulations of the U.S.

Securities and Exchange Commission ("SEC").

All intercompany balances and transactions have been eliminated in consolidation.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of expenses during the reporting period.

Significant estimates and assumptions made in the accompanying financial statements include but are not limited to advance payments and accruals related to the Company’s research and development expenses .

The preparation of consolidated financial statements in conformity with accounting principles generally accepted in the United States of America (GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of expenses during the reporting period.

Significant estimates and assumptions made in the accompanying consolidated financial statements include but are not limited to advance payments and accruals related to the Company’s research and development expenses .

The Company evaluates its estimates and assumptions on an ongoing basis using historical experience and other factors and adjusts those estimates and assumptions when facts and circumstances dictate.

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Financial instruments, which potentially subject the Company to significant concentrations of credit risk, consist of cash and cash equivalents, which are invested in U.S.

treasury-based money market funds, and available-for-sale debt securities, which are invested in U.S.

treasury-based money market funds.

As of December 31, 2023, the Company held available-for-sale securities, which were invested in U.S.

treasury securities.

These investments matured in 2024.

A portion of the Company’s cash is maintained at two federally insured financial institutions, and account balances may at times exceed federally insured limits.

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Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

The Company has leases related to its facilities used for offices, laboratory space and manufacturing, which are classified as operating leases.

These leases result in operating right-of-use (ROU) assets, current operating lease liabilities, and non-current operating lease liabilities in the accompanying balance sheets.

The Company does not have any financing leases.

Leases with terms of 12 months or less are considered short-term leases and ROU assets and lease obligations are not recognized.

The Company has leases related to its facilities used for offices and laboratory space, which are classified as operating leases as well as leases related to its manufacturing arrangements, which are classified as finance leases.

At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease and its classification based on the unique facts and circumstances present in the arrangement.

Leases with a term greater than one year are recognized on the balance sheet as right-of-use assets and current and non-current lease liabilities, as applicable.

Lease liabilities and their corresponding right-of-use assets are initially recorded based on the present value of lease payments over the expected remaining lease term.

Certain adjustments to the right-of-use asset may be required for items such as incentives received.

The interest rate implicit in lease contracts is typically not readily determinable.

As a result, the Company utilizes its incremental borrowing rate to discount lease payments.

Subsequent to the initial measurement, the Company will continue to account for:

• the lease liability at the net present value using the incremental borrowing rate that was in effect as of the lease commencement, lease modification, or transition date, and;

• the finance lease and operating lease expense on a straight line basis.

Leases with terms of 12 months or less are considered short-term leases and right-of-use assets and lease obligations are not recognized.

Payments associated with short-term leases are expensed on a straight-line basis over the lease term.

ROU assets represent the right to use an underlying asset for the lease term and the lease liabilities represent an obligation to make lease payments arising from the lease.

Lease liabilities are measured at the present value of the lease payments not yet paid discounted using the discount rate for the lease established at the lease commencement date.

Operating lease ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the life of the lease term.

To determine the present value, the implicit rate is used when readily determinable.

For those leases where the implicit rate is not provided, the Company determines an incremental borrowing rate based on information available at the lease commencement date.

The operating lease ROU assets also include any prepaid lease payments made and any other indirect costs and excludes any lease incentives received.

Lease terms may include the impact of options to extend or terminate the lease when it is reasonably certain that the

Company will exercise those options.

Lease cost for operating leases is recognized on a straight-line basis over the lease term.

The Company aggregates all lease and non-lease components for each class of underlying assets into a single lease componen t .

In accordance with ASC 842, components of a lease should be split into three categories:

lease components, non-lease components and non-components.

The fixed and in-substance fixed contract consideration (including any consideration related to non-components) must be allocated based on the respective relative fair values to the lease components and non-lease components.

Entities may elect not to separate lease and non-lease components.

Rather, entities would account for each lease component and related non-lease component together as a single lease component.

The Company has elected to aggregate all lease and non-lease components for each class of underlying assets into a single lease component for real-estate leases and embedded manufacturing arrangements.

ASC 842 allows for the use of judgment in determining whether the assumed lease term is for a major part of the remaining economic life of the underlying asset and whether the present value of lease payments represents substantially all of the fair value of the underlying asset.

The Company applies the guidance in ASC 842-10-55-2 to assist in determining lease classification across its leases.

Research and Development Expenses

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The Company records accrued liabilities for estimated costs of research and development activities conducted by service providers, which include preclinical studies, contract manufacturing activities and clinical trial activities.

The Company records the estimated costs of research and development activities based upon the estimated amount of services provided and includes these costs in accrued and other current liabilities in the accompanying balance sheets and within research and development expense in the accompanying statements of operations.

The Company records the estimated costs of research and development activities based upon the estimated amount of services provided and in accordance with agreements established with service providers and includes these costs in accrued and other current liabilities in the accompanying balance sheets and within research and development expense in the accompanying statements of operations.

Non-refundable advance payments made for goods or services that will be used or rendered for future research and development activities are deferred and capitalized and recognized as expense as the goods are received or the related services are rendered.

The Company accrues for these costs based on factors such as estimates of the work completed and in accordance with agreements established with service providers.

The Company makes significant judgments and estimates in determining the accrued liabilities and prepaid expenses in each reporting period.

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The Company uses the asset and liability method of accounting for income taxes.

Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax base, as well as for net operating loss carryforwards and research and development credits, and are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled.

Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to temporary differences between the consolidated financial statement carrying amounts of existing assets and liabilities and their respective tax base, as well as for net operating loss carryforwards and research and development credits, and are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled.

Valuation allowances are established when necessary to reduce deferred tax assets where, based upon the available evidence, the Company concludes that it is more-likely-than-not that the deferred tax assets will not be realized.

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Net Loss Per Share

The Company calculates basic and diluted net loss per share in conformity with the two-class method required for participating securities.

The Company has voting and non-voting common stock.

The Company calculates basic and diluted net loss per share in conformity with the two-class method required for participating securities because the Company had both voting and non-voting common stock outstanding in 2023 and for a portion of 2024.

The rights, including the liquidation and dividend rights, of the holders of the voting and non-voting common stock are identical, except with respect to voting.

Each share of non-voting common stock may be converted at any time into one share of voting common stock at the option of its holder by providing written notice to the Company, subject to the limitations provided for in the amended and restated certificate of incorporation.

Basic net loss per share attributable to common stockholders is computed by dividing the net loss by the weighted average number of shares of common stock, including pre-funded warrants to purchase shares of common stock that were issued in a financing transaction in December 2022.

As of December 31, 2024, no shares of non-voting common stock remain outstanding.

Basic net loss per share attributable to common stockholders is computed by dividing the net loss by the weighted average number of shares of common stock, including any pre-funded warrants to purchase shares of common stock that may be outstanding.

The undistributed loss for each year is allocated to common stockholders based on the contractual participation rights of the voting and non-voting common stock as if the losses for the year had been distributed.

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Operating segments are defined as components of an entity for which separate financial information is available and that is regularly reviewed by the Chief Operating Decision Maker (CODM) in deciding how to allocate resources to an individual segment and in assessing performance.

The Company’s CODM is its Chief Executive Officer.

The Company’s CODM is its Chief Executive Officer (CEO).

The Company has determined it operates in a single operating segment and has one reportable segment.

Refer to Note 8 – Segment Reporting for further information related to our segment.

Deferred Offering Costs

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Emerging Growth Company Status

The Company is an emerging growth company, as defined in the Jumpstart Our Business Startups Act of 2012 (the JOBS Act).

Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued subsequent to the enactment of the JOBS Act, until such time as those standards apply to private companies.

The Company has elected to use this extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that it (i) is no longer an emerging growth company or (ii) affirmatively and irrevocably opts out of the extended transition period provided in the JOBS Act.

As a result, these financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates.

Recently Issued Accounting Pronouncements

In November 2023, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update, or ASU, 2023-07, Segment Reporting (Topic 280) – Improvements to Reportable Segment Disclosures .

Prior to December 31, 2024, the Company was an “emerging growth company” (EGC) as defined in the Jumpstart Our Business Startups Act, (JOBS Act), and elected to take advantage of certain exemptions from various reporting requirements that are applicable to other public companies until the Company no longer qualifies as an EGC, including using the extended transition period for complying with new or revised accounting standards.

As of December 31, 2024, the Company ceased to qualify as an EGC.

Recently Adopted Accounting Pronouncements

In November 2023, the FASB issued Accounting Standards Update, or ASU, 2023-07, Segment Reporting (Topic 280) – Improvements to Reportable Segment Disclosures .

This ASU requires that a public entity provide additional segment disclosures on an interim and annual basis.

The amendments in this ASU should be applied retrospectively to all prior periods presented in the financial statements, unless impracticable.

The amendments in this ASU should be applied retrospectively to all prior periods presented in the consolidated financial statements, unless impracticable.

Upon transition, the segment expense categories and amounts disclosed in the prior periods should be based on the significant segment expense categories identified and disclosed in the period of adoption.

The ASU is effective for fiscal years beginning after December 15, 2023 and interim periods within fiscal years beginning after December 15, 2024.

Early adoption is permitted.

The Company is currently planning to adopt this guidance when effective and is assessing the impact of the adoption on the Company’s financial statements and accompanying footnotes.

The Company adopted this ASU for the annual period ended December 31, 2024 and the amendments have been applied retrospectively to all prior periods presented in the financial statements.

Refer to Note 8 – Segment Reporting for further information related to our segment.

Recently Issued Accounting Pronouncements

In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures .

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Early adoption is permitted.

The Company is currently planning to adopt this guidance when effective and is assessing the impact of the adoption on the Company’s financial statements and accompanying footnotes.

This update is effective beginning with the Company’s 2025 fiscal year annual reporting period.

The Company is currently planning to adopt this guidance when effective and is assessing the impact of the adoption on the Company’s consolidated financial statements and accompanying footnotes.

In November 2024, the FASB issued ASU 2024-03, Income Statement (Subtopic 220-40):

Reporting Comprehensive Income-Expense Disaggregation Disclosures.

ASU 2024-03 requires enhanced disclosures about components of expense captions on the face of the income statement.

This standard will be effective for fiscal years beginning after December 15, 2026.

Early adoption is permitted.

ASU 2024-03 applies on a prospective basis for periods beginning after the effective date.

However, retrospective application to any or all prior periods presented is permitted.

The Company is currently planning to adopt this guidance when effective and is assessing the impact of the adoption on the Company’s consolidated financial statements and accompanying footnotes.

There have been no other new accounting pronouncements or changes to accounting pronouncements that, if adopted, would have or may have a material impact on the Company’s consolidated statements or disclosures.

Fair Value Measurements

As of December 31, 2024 and 2023, the Company’s financial instruments included cash and cash equivalents, available-for-sale debt securities, accounts payable and accrued expenses.

The carrying amounts for cash and cash equivalents, accounts payable and accrued expenses reported in the Company’s financial statements for these instruments approximate their respective fair values because of the short-term nature of these instruments.

The carrying amounts for cash and cash equivalents, accounts payable and accrued expenses reported in the Company’s consolidated financial statements for these instruments approximate their respective fair values because of the short-term nature of these instruments.

The following tables present information about the Company’s financial assets measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values:

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Active Markets

for Identical

Assets (Level 1)

for Identical Assets

Financial assets

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Money market funds

Treasury securities - original maturity less than three months

Short-term investments:

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Active Markets

for Identical

Assets (Level 1)

for Identical Assets

Financial assets

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Money market funds

Treasury securities - original maturity less than three months

Short-term investments:

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For debt securities classified as available-for-sale investments, the Company records unrealized gains or losses resulting from changes in fair value between measurement dates as a component of other comprehensive income.

The Company did not hold any available-for-sale securities as of December 31, 2024:

December 31, 2023

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Included in short-term investments

December 31, 2022

Amortized Cost

Gross Unrealized Gains

Gross Unrealized Losses

Financial assets

Money market funds

Included in cash and cash equivalents

Treasury securities - due in one year or less

Included in short-term investments

Property, Plant and Equipment

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Furniture and fixtures

Leasehold improvements

Computer equipment

Leasehold improvements

Total property, plant and equipment

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In May 2020, the Company amended its Addendum with the Center for Advanced Retinal and Ocular Therapeutics (CAROT) to expand access to vector manufacturing.

Research and development expense related to executed addenda under the master translational research service agreements with Penn recognized in the accompanying statements of operations for the years ended December 31, 2023 and 2022 was $ 3,786 and $ 2,623 , respectively.

Research and development expense related to executed addenda under the master translational research service agreements with Penn recognized in the accompanying statements of operations was $ 3,250 and $ 3,786 for the years ended December 31, 2024 and 2023, respectively.

The Company is committed to pay up to $ 3,000 under the CARTA Services Agreement for cell processing manufacturing through December 31, 2025.

The Company may incur additional expenses of approximately $ 643 through the remaining term of the CAROT Amended Addendum.

The Company may incur additional expenses up to $ 643 t hrough the remaining term of the CAROT Amended Addendum.

Exclusive License Agreement with IASO Biotherapeutics

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Upon the U.S.

Food and Drug Association’s clearance of the CABA-201 Investigational New Drug application for the treatment of systemic lupus erythematosus in March 2023, a milestone payment of $ 1,000 was recognized in the accompanying statements of operations.

No amount was owed to IASO as of December 31, 2023.

A milestone payment of $ 1,500 was paid to IASO in the first quarter of 2024 after the first patient in a CABA-201 trial was dosed.

Food and Drug Association’s clearance of the rese-cel Investigational New Drug application for the treatment of systemic lupus erythematosus in March 2023, a milestone payment of $ 1,000 was recognized in the accompanying statements of operations.

A milestone payment of $ 1,500 was paid to IASO in the first quarter of 2024 after the first patient in a rese-cel trial was dosed.

IASO has the right of first negotiation if the Company desires to grant a third party an exclusive license to develop, manufacture, commercialize or otherwise exploit the licensed products in the Greater China region.

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IASO may also terminate the Agreement if the Company fails to achieve certain specified diligence milestones in a timely manner and/or if the Company commences any patent challenges with respect to the patents and patent applications relating to the licensed sequence, in each case upon advance written notice.

Artisan Collaboration and License Agreement

In July 2020 and as amended in January 2023, the Company entered into a collaboration and license agreement with Artisan Bio, Inc.

(Artisan), wherein the Company and Artisan agreed to collaborate to potentially enhance certain pipeline products of the Company at specific targets using Artisan’s gene editing and engineering technology.

If the Artisan technology is applied to any of the Company’s products, the Company will be responsible for the development, manufacturing, and commercialization of any such products.

Under the terms of the agreement, the Company was required to pay Artisan a nominal upfront fee, as well as costs associated with research and development activities.

Artisan is eligible to receive future development and regulatory milestones, and is also eligible to receive sales milestones and tiered royalties on net sales of products that incorporate the Artisan technology.

The Company can terminate the agreement at will upon advance written notice at no cost.

In January 2024, the Company was notified that the agreement would be assigned in connection with Artisan's general assignment for the benefit of creditors.

The agreement remains effective.

Licence and Supply Agreement with Oxford Biomedica

In December 2021, the Company entered into a Licence and Supply agreement (LSA) with Oxford Biomedica (UK) Limited (Oxford), wherein the LSA grants the Company a non-exclusive license to Oxford’s LentiVector® platform for its application in the Company’s DSG3-CAART program and puts in place a multi-year vector supply agreement.

Under the terms of the agreement, the Company was required to pay Oxford an upfront fee, as well as costs associated with initial vector manufacturing activities for a total cost of up to approximately $ 4,000 , of which project to date expense of $ 1,100 has been recognized.

Under the terms of the agreement, the Company was required to pay Oxford an upfront fee, as well as costs associated with initial vector manufacturing activities for a total cost incurred of $ 1,100 .

Oxford is eligible to receive regulatory and sales milestones in the low tens of millions and royalties in the low single digits on net sales of products that incorporate the Oxford technology.

The Company can terminate the agreement at will upon advance written notice and subject to certain manufacturing slot cancellation fees.

In May 2023, the Company amended the LSA with Oxford to expand the license to include the Company's CABA-201 program for an upfront fee of $ 500 and in August 2023, the Company and Oxford entered into a vector supply agreement for CABA-201, and a related second amendment to the LSA, with a total cost under the vector supply agreement of up to approximately $ 5,000 , of which approximately $ 1,520 was recognized as expense in the accompanying statements of operations for the year ended December 31, 2023.

In February 2024, the Company and Oxford entered into a third amendment of the LSA to update the patent schedule.

In May 2023, the Company amended the LSA with Oxford to expand the license to include the Company's rese-cel program for an upfront fee of $ 500 , and in August 2023, the Company and Oxford entered into a vector supply agreement for rese-cel, and a related second amendment to the LSA, with a total cost under the vector supply agreement of up to approximately $ 5,000 , of which approximately $ 3,500 and $ 1,500 were recognized as research and development expense for the years ended December 31, 2024 and 2023, respectively.

In February 2024, the Company and Oxford entered into a third amendment to the LSA to update the patent schedule.

In June 2024, the Company and Oxford entered into a fourth amendment to the LSA elimin ating royalties on net sales of products that incorporate the Oxford technology if Oxford manufactures the vector.

In December 2024, the Company and Oxford entered into a work order with a cost of approximately $ 9,000 for certain process characterization activities as part of commercial readiness activities.

The Company can terminate the LSA or any work order under the LSA at will upon advance written notice and subject to certain cancellation fees.

Option and License Agreement with Autolus

In January 2023, the Company entered into an Option and License Agreement (Autolus Agreement) with Autolus Holdings (UK) Limited (Autolus), wherein the Autolus Agreement granted the Company a non-exclusive license to access Autolus' RQR8 technology in its CD19-CAR T cell therapy program, and subject to additional nominal option exercise fees, up to four additional targets.

Under the terms of the Autolus Agreement, the Company was required to pay Autolus an upfront license fee of $ 1,200 , recognized as expense in the first quarter of 2023 in the accompanying statements of operations, of which $ 1,100 was paid in 2023 and $ 100 was paid in January 2024.

In January 2025, the Company and Autolus agreed to novate the Autolus Agreement with both Autolus and Autolus Limited jointly assuming the rights, obligations and liabilities of Autolus, under the Autolus Agreement.

Under the terms of the Autolus Agreement, the Company was required to pay Autolus an upfront license fee of $ 1,200 that was recognized as expense in the first quarter of 2023 in the accompanying statements of operations, of which $ 1,100 was paid in 2023 and $ 100 was paid in January 2024.

Autolus is also eligible to receive regulatory milestones of up to $ 12,000 for each licensed target, sales milestones of up to a total of $ 15,000 and royalties in the low single digits on net sales of all products that incorporate the RQR8 technology.

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Commitments and Contingencies

Manufacturing Agreement

Manufacturing Agreements

In January 2021, the Company entered into a Development and Manufacturing Services Agreement (WuXi Agreement) with WuXi Advanced Therapies, Inc.

(WuXi) to serve as an additional cell processing manufacturing partner for the MuSK-CAART Phase 1 clinical trial, or MusCAARTes TM trial.

The WuXi Agreement is scheduled to expire upon completion of WuXi’s services related to MuSK-CAART and CABA-201.

In August 2023, the Company

entered into new work orders under the WuXi Agreement for WuXi to serve as one of the Company’s cell processing manufacturing partners for the planned global clinical development of CABA-201 in multiple indications, including potential late-stage clinical trials and commercial readiness activities for CABA-201.

Under the August 2023 work orders, WuXi converted the Company’s non-dedicated suite to a dedicated suite for GMP manufacturing for the Company’s CABA-201 and MuSK-CAART programs, or the Dedicated Suite, for an initial term of 18 months with two 18-month extensions at the Company’s sole option on six months' notice prior to the end of the term.

The WuXi Agreement is scheduled to expire upon completion of WuXi's services related to MuSK-CAART and rese-cel.

In August 2023, and as extended in August 2024, the Company entered into an agreement with WuXi to serve as one of the Company's manufacturing partners for the global clinical development of rese-cel in multiple indications, including potential late-stage clinical trials and commercial readiness activities for rese-cel.

Under the August 2023 work orders, WuXi converted the Company’s non-dedicated suite to a dedicated suite for GMP manufacturing for the Company’s rese-cel and MuSK-CAART programs, or the Dedicated Suite, for an initial term of 18 months with two 18-month extensions at the Company’s sole option on six months' notice prior to the end of the term.

In August 2024, the Company sent a notice to WuXi to extend the initial term of the WuXi Agreement by 18 months through August 2026.

In addition, the Company agreed to certain monthly minimum runs.

In lieu of the original $ 1,500 termination fee under the terms of the WuXi Agreement, the Company would incur a $ 1,080 termination fee if it terminates both the CABA-201 and MuSK-CAART work orders for any reason.

The Company may terminate for convenience the WuXi Agreement or any work order with six months' prior written notice, however, the Company may not terminate the Dedicated Suite without terminating both the MuSK-CAART and CABA-201 GMP run work orders.

In August 2024, the 2023 work order related to GMP manufacturing was amended to reduce the minimum monthly runs through the end of 2024.

In lieu of the original $ 1,500 termination fee under the terms of the WuXi Agreement, the Company would incur up to a $ 1,080 termination fee if it terminates both the rese-cel and MuSK-CAART work orders for any reason.

The Company may terminate for

convenience the WuXi Agreement or any work order with six months' prior written notice.

However, the Company may not terminate the Dedicated Suite without terminating both the MuSK-CAART and rese-cel GMP run work orders.

WuXi may terminate for convenience the WuXi Agreement or any work order on 18 months' prior written notice, but such notice may not be effective prior to February 2028.

In December 2024, the Company entered into a Development and Manufacturing Services Agreement (the Lonza Agreement) with Lonza Houston Inc.

(Lonza) to serve as one of the Company's manufacturing partners for the global clinical development of rese-cel in multiple indications, including potential late-stage clinical trials and preparations for commercial readiness.

Under the initial work order, Lonza will perform cell therapy manufacturing activities for Cabaletta’s CAR-T cell therapy product rese-cel for a term of 12 months and total cost of approximately $ 16,000 with the ability to extend the manufacturing period subject to the terms of the Lonza Agreement.

Other Purchase Commitments

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Indemnification

The Company enters into certain types of contracts that contingently requires the Company to indemnify various parties against claims from third parties.

These contracts primarily relate to (i) the Company’s bylaws, under which the Company must indemnify directors and executive officers, and may indemnify other officers and employees, for liabilities arising out of their relationship, (ii) contracts under which the Company must indemnify directors and certain officers and consultants for liabilities arising out of their relationship, (iii) contracts under which the Company may be required to indemnify partners against certain claims, including claims from third parties asserting, among other things, infringement of their intellectual property rights, and (iv) procurement, consulting, or license agreements under which the Company may be required to indemnify vendors, consultants or licensors for certain claims, including claims that may be brought against them arising from the Company’s acts or omissions with respect to the supplied products, technology or services.

The Company enters into certain types of contracts that contingently require the Company to indemnify various parties against claims from third parties.

These contracts primarily relate to (i) the Company’s Amended and Restated Bylaws, as amended, (bylaws) under which the Company must indemnify directors and executive officers, and may indemnify other officers and employees, for liabilities arising out of their relationship, (ii) contracts under which the Company must indemnify directors and certain officers and consultants for liabilities arising out of their relationship, (iii) contracts under which the Company may be required to indemnify partners against certain claims, including claims from third parties asserting, among other things, infringement of their intellectual property rights, and (iv) procurement, consulting, or license agreements under which the Company may be required to indemnify vendors, consultants or licensors for certain claims, including claims that may be brought against them arising from the Company’s acts or omissions with respect to the supplied products, technology or services.

From time to time, the Company may receive indemnification claims under these contracts in the normal course of business.

In addition, under these contracts, the Company may have to modify the accused infringing intellectual property and/or refund amounts received.

In the event that one or more of these matters were to result in a claim against the Company, an adverse outcome, including a judgment or settlement, may cause a material adverse effect on the Company’s future business, operating results or financial condition.

In the event that one or more of these matters were to result in a claim against the Company, an adverse outcome, including a judgment or settlement, may have a material adverse effect on the Company’s future business, operating results or financial condition.

It is not possible to determine the maximum potential amount under these contracts due to the limited history of prior indemnification claims and the unique facts and circumstances involved in each particular agreement.

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While the outcome of any such proceedings cannot be predicted with certainty, as of December 31, 2024, the Company is not involved in any material litigation or legal proceedings that it would expect to have a material adverse impact on its financial position, results of operations, or cash flows.

The Company determines whether an arrangement is or contains a lease based on the unique facts and circumstances present at the inception of an arrangement.

The Company leases office and laboratory space and a

dedicated manufacturing suite at WuXi under operating leases that have a weighted average remaining term of 1.5 years and 2.5 years as of December 31, 2023 and 2022, respectively.

As described further in Note 7, in August 2023, the Company entered into new work orders under the WuXi Agreement for WuXi to serve as one of the Company’s cell processing manufacturing partners for the global clinical development of CABA-201.

WuXi converted the Company’s non-dedicated suite to a Dedicated Suite for GMP manufacturing for the Company’s CABA-201 and MuSK-CAART programs, for an initial term of 18 months.

The terms of the August 2023 work orders included both fixed costs and contingent variable costs.

The lease commenced October 1, 2023, and a right of use asset and lease liability of $ 953 was initially recorded for the fixed payments.

Subsequent to December 31, 2023, the contingency related to the variable costs was resolved which resulted in an additional $ 4,350 in fixed undiscounted lease payments which will be made through the end of the lease.

The Company may terminate for convenience with six months’ prior written notice and a $ 1,080 termination fee, the Dedicated Suite lease if both the CABA-201 and MuSK-CAART work orders are terminated.

The Company also leases office space under short-term leases that provide for either party to terminate the lease without cause and with 30 days’ notice.

The Company’s operating leases include rent escalations and are subject to additional variable charges, including common area maintenance, property taxes and property insurance.

Segment Information

Operating segments are defined as components of an entity for which separate financial information is available and that is regularly reviewed by the CODM in deciding how to allocate resources to an individual segment and in assessing performance.

The Company’s CODM is the CEO.

The Company has determined that it has one operating and reportable segment.

The segment consists of the development of clinical and preclinical product candidates for the discovery and development of innovative engineered T cell therapies and related administrative activities.

CODM assesses performance and allocates resources based on the Company’s consolidated statement of operations, which is reported on the income statement as consolidated net loss and considers forecast-to-actuals variances on a quarterly basis for expenses that are deemed significant.

Further, the CODM reviews the segment’s assets based on the consolidated balance sheet to assess liquidity and funding capacity.

The majority of the Company's assets are located in the United States.

The Company’s CODM views specific categories within expenses as significant given the direct correlation between cash burn and profitability as a pre-revenue company.

Significant segment expenses, as provided to the CODM, are presented below.

For additional information on the year over year change of segment expenses refer to Item 7.

Management’s Discussion and Analysis of Financial Condition and Results of Operations.

Year Ended December 31,

(in thousands)

Research and development expenses:

Clinical trials

Development services

Manufacturing of preclinical and clinical supplies

License of intellectual property

Other research and development costs (1)

General and administration expenses

Interest income

Interest expense

(1) Other research and development costs includes costs associated with information technology, travel, medical and scientific symposiums and conferences.

The Company leases office and laboratory space in addition to a manufacturing agreement which has been determined to contain an embedded lease.

Operating lease commitments

The Company leases office and laboratory space which include rent escalations and are subject to additional variable charges, including common area maintenance, property taxes and property insurance.

Given the variable nature of such costs, they are recognized as expense as incurred.

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The Company has elected the practical expedient to account for lease and non-lease components as a single-lease component and has included fixed payments related to non-lease components in calculating the operating lease liability.

The weighted average discount rate for the Company’s operating leases is 9.5 % and 8.3 % as of December 31, 2023 and 2022, respectively, representing the Company's incremental borrowing rate at the beginning of each lease.

For the year ended December 31, 2023, total lease cost was $ 3,259 , consisting of $ 2,477 operating lease costs, $ 65 of variable lease costs and $ 717 of short-term lease cost.

Cash paid for amounts included in the measurement of operating lease liabilities was $ 2,456 and $ 2,910 for the years ended December 31, 2023 and 2022, respectively.

For the year ended December 31, 2022, total lease cost was $ 3,849 , consisting of $ 3,042 operating lease costs, $ 36 of variable lease costs and $ 771 of short-term lease cost.

Future lease payments under the non-cancelable operating leases as of December 31, 2023 are as follows :

In 2024, the Company extended the terms of its lab and office operating leases and leased additional lab space resulting in an increase in the right-of-use asset and lease liability of $ 4,242 .

Finance lease commitments - Embedded leases

WuXi converted the Company’s non-dedicated suite to a Dedicated Suite for GMP manufacturing for the Company’s rese-cel and MuSK-CAART programs, for an initial term of 18 months.

The terms of the August 2023 work orders included both fixed costs and contingent variable costs.

The lease commenced October 1, 2023.

In 2024, the Company remeasured the lease due to resolution of the contingency related to variable costs and an amendment to the 2023 work order to extend the term of the agreement for an additional 18 months through August

2026 resulting in an increase in the right-of-use asset and lease liability of $ 10,963 .

The Company may terminate the Dedicated Suite lease for convenience with six months’ prior written notice and up to a $ 1,080 termination fee if both the rese-cel and MuSK-CAART work orders are terminated .

As described further in Note 7, in December 2024, the Company entered into the Lonza Agreement with Lonza to serve as one of our manufacturing partners.

Under the initial work order, Lonza will perform cell therapy manufacturing activities for our CAR-T cell therapy product rese-cel for a term of 12 months and total cost of approximately $ 16,000 with the ability to extend the manufacturing period subject to the terms of the Lonza Agreement.

The Lonza Agreement is currently being evaluated for lease accounting under ASC 842.

No right-of-use asset or liability was recognized as of December 31, 2024, as lease commencement begins in fiscal year 2025.

Summary of lease costs recognized under ASC 842

The following table contains a summary of the lease costs recognized under ASC 842 and other information pertaining to the Company’s operating and finance leases for the years ended December 31, 2024 and 2023.

For the year ended December 31,

Finance leases

Interest expense

Amortization expense

Total fixed finance lease cost

Variable lease cost

Total finance lease cost

Operating leases

Fixed lease cost

Total fixed operating lease cost

Variable lease cost

Short-term lease cost

Total operating lease cost

Cash paid in the measurement of lease liabilities

Operating cash flows used for operating leases

Operating cash flows used for finance leases

Financing cash flows for finance leases

Other information

Weighted average remaining lease term - finance leases (in years)

Weighted average discount rate - finance leases

Weighted average remaining lease term - operating leases (in years)

Weighted average discount rate - operating leases

For finance leases embedded in CDMO arrangements, interest expense is recognized using the effective interest method, applying the Company's incremental borrowing rate as required by ASC 842, and amortization expense is recognized on a straight-line basis over the shorter of the life of the asset or the term of the lease.

Future lease payments under the non-cancelable operating and finance leases as of December 31, 2024 are as follows :

Finance Leases

Operating Leases

Total undiscounted lease payments

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Holders of voting common stock shall have the exclusive right to vote for the election of directors of the Company and on all other matters requiring stockholder action.

Each share of the Company’s non-voting common stock may be converted at any time into one share of common stock at the option of its holder by providing written notice to the Company , subject to the limitations provided for in the amended and restated certificate of incorporation.

Each share of the Company’s non-voting common stock may be converted at any time into one share of common stock at the option of its holder by providing 61 days written notice to the Company , subject to certain limitations, as described in the amended and restated certificate of incorporation.

In May 2024, 1,444,295 shares of non-voting common stock was converted to voting common stock and no shares of non-voting common stock remain outstanding.

May 2023 Financing

In May 2023, the Company issued 8,337,500 shares of its common stock in an underwritten public offering, including the exercise in full by the underwriters of their option to purchase an additional 1,087,500 shares, at a public

offering price of $ 12.00 per share.

Aggregate net proceeds were $ 93,755 after deducting underwriting discounts and commissions and offering expenses of $ 6,295 .

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The purchase price per share of each pre-funded warrant represents the per share offering price for the common stock, minus the $ 0.00001 per share exercise price of such pre-funded warrant.

Aggregate net proceeds were $ 32,562 after deducting underwriting discounts and commissions and offering expenses.

As of December 31, 2023, 5,045,722 pre-funded warrants had been exercised and 1,168,054 remain outstanding.

Aggregate net proceeds were $ 32,562 after deducting underwriting discounts and commissions and offering expens es.

As of December 31, 2024, 6,213,775 pre-funded warrants had been exercised and no warrants remain outstanding.

The pre-funded warrants were classified as a component of permanent stockholders’ equity within additional paid-in capital and were recorded at the issuance date using a relative fair value allocation method.

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At-the-Market Offering

On March 16, 2023, the Company filed a Shelf Registration Statement in relation to the registration of common stock, preferred stock, debt securities, warrants and/or units of any combination thereof for the purposes of selling, from time to time, the Company’s common stock, debt securities or other equity securities in one or more offerings.

This S-3 was declared effective on April 26, 2023.

The Company has a Sales Agreement with Cowen and Company, LLC, or Cowen, to provide for the offering, issuance and sale of up to an aggregate amount of $ 100.0 million of common stock from time to time in “at-the-market” offerings (the ATM Program) pursuant to its shelf registration statement on Form S-3 (File No.

333-270599), which was declared effective April 26, 2023, and subject to the limitations thereof.

On March 21, 2024, the Company filed an automatic shelf registration statement (S-3ASR) in relation to the registration of common stock, preferred stock, debt securities, warrants and/or units of any combination thereof for the purposes of selling, from time to time, the Company’s common stock, debt securities or other equity securities in one or more offerings.

This S-3ASR became effective immediately.

We intend to convert the S-3ASR to S-3 by post-effective amendments in connection with the filing of this Annual Report.

The Company has a Sales Agreement with Cowen and Company, LLC (Cowen) to provide for the offering, issuance and sale of up to an aggregate amount of $ 200.0 million of common stock from time to time in “at-the-market” offerings (2024 ATM Program) pursuant to its S-3ASR, and subject to the limitations thereof.

In December 2024, the Company sold 1,225,000 shares pursuant to the 2024 ATM Program for net proceeds of $ 5,129 , after deducting commissions of $ 105 .

The Company previously had a Sales Agreement with Cowen to provide for the offering, issuance and sale of up to an aggregate amount of $ 100.0 million of common stock from time to time in “at-the-market” offerings (2023 ATM Program) pursuant to its shelf registration statement on Form S-3 (File No.

333-270599), which was declared effective April 26, 2023.

During the year ended December 31, 2023, the Company sold 4,760,899 shares pursuant to the 2023 ATM Program for net proceeds of $ 91,740 , after deducting commissions of $ 2,352 .

Subsequent to December 31, 2023, the Company sold 258,070 additional shares, completing the ATM Program for net proceeds of $ 5,746 , after deducting commissions of $ 147 .

On May 10, 2023, the Company delivered written notice to Cowen that it was terminating the Sales Agreement dated November 10, 2020 (the 2020 Sales Agreement), by and between the Company and Cowen.

Upon waiver of the notice period by Cowen, the termination was effective as of May 10, 2023 (the Termination Date).

All of the continuing obligations under the 2020 Sales Agreement were terminated as of the Termination Date, other than those provisions which expressly survive termination as provided in the 2020 Sales Agreement.

The Company was not subject to any termination penalties related to the termination of the 2020 Sales Agreement.

Prior to termination, 4,792,562 shares of common stock, $ 0.00001 par value per share, had been sold pursuant to the 2020 Sales Agreement.

As a result of the termination of the 2020 Sales Agreement, the Company will not offer or sell any additional shares under the 2020 Sales Agreement.

In the first quarter of 2024, the Company sold 258,070 additional shares, completing the 2023 ATM Program for net proceeds of $ 5,746 , after deducting commissions of $ 147 .

2018 Stock Option and Grant Plan

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The 2019 Plan provides for the grant of incentive stock options, nonqualified stock options, stock appreciation rights, restricted stock units, restricted stock awards, unrestricted stock awards, cash-based awards and dividend equivalent rights to the Company’s officers, employees, directors and consultants.

The number of shares initially reserved for issuance under the 2019 Plan was 2,342,288 ,

which will be increased each January 1 thereafter by 4 % of the number of shares of the Company’s common stock outstanding on the immediately preceding December 31 or such lesser number of shares determined by the Company’s board of directors or compensation committee of the board of directors.

The number of shares initially reserved for issuance under the 2019 Plan was 2,342,288 , which will be increased each January 1 thereafter by 4 % of the number of shares of the Company’s common stock outstanding on the immediately preceding December 31 or such lesser number of shares determined by the Company’s board of directors or compensation committee of the board of directors.

On June 1, 2023, at the 2023 Annual Meeting of Stockholders of the Company, the stockholders of the Company approved Amendment No.

1 unchanged sentence

On January 1, 2025, the total number of shares under the 2019 Plan was increased by 2,029,724 shares pursuant to the 2019 Plan Evergreen Provision.

As of December 31, 2023, there were 2,767,184 shares remaining available for issuance.

As of December 31, 2024, there were 1,379,305 shares remaining available for issuance under the 2019 Plan.

A summary of the stock option activity is presented below:

34 unchanged sentences

The 2019 Employee Stock Purchase Plan (2019 ESPP) was approved by the Company’s board of directors on October 14, 2019, and became effective on October 23, 2019.

A total of 234,229 shares of common stock were initially reserved for issuance under the 2019 ESPP, and will be increased each January 1 thereafter through January 1, 2029 by the least of (i) 234,229 shares of common stock, (ii) 1 % of the number of shares of the Company’s common stock outstanding on the immediately preceding December 31 or (iii) such lesser number of shares determined by the 2019 ESPP’s administrator.

On January 1, 2024, there was no increase to the total number of shares under the 2019 ESPP.

As of December 31, 2023, there were 372,315 shares remaining available for issuance.

A total of 234,229 shares of common stock were initially reserved for issuance under the 2019 ESPP, and such number of shares will be increased each January 1 thereafter through January 1, 2029 by the least of (i) 234,229 shares of common stock, (ii) 1 % of the number of shares of the Company’s common stock outstanding on the immediately preceding December 31 or (iii) such lesser number of shares determined by the 2019 ESPP’s administrator.

There was no increase to the total number of shares available under the 2019 ESPP on January 1, 2024, 2023 or 2022, respectively.

As of December 31, 2024, there were 314,259 shares remaining available for issuance under the 2019 ESPP.

Employee contributions are made through payroll deductions of up to 15 % of eligible compensation over the offering period.

1 unchanged sentence

At the end of each offering period, shares of the Company’s common stock may be purchased at 85 % of the lesser of the Company’s common stock on (i) the first trading day of the relevant offering period and (ii) the last trading day of the relevant offering period.

The first offering period commenced on July 1, 2020 and ended on November 30, 2020.

Thereafter, offerings will be six months in duration and will commence on each December 1 and June 1.

Each offering period will be six months in duration and will commence on each December 1 and June 1.

The reconciliation of federal statutory income tax rate to the Company’s effective income tax rate is as follows:

28 unchanged sentences

The state net operating losses begin to expire in 2037 .

The local net operating losses began to expire in 2024 .

As of December 31, 2023, the Company had federal and state research and development tax credit carryforwards of $ 9,923 and $ 269 , respectively, which begin to expire in 2038 .

The local net operating losses begin to expire in 2042 .

As of December 31, 2024, the Company had federal and state research and development tax credit carryforwards of $ 15,684 and $ 612 , respectively, which begin to expire in 2038 and 2036 , respectively.

Under the provisions of Sections 382 and 383 of the Internal Revenue Code of 1986, as amended (the IRC), these net operating losses, credit carryforwards and other tax attributes may be subject to limitation based on previous significant changes in ownership and upon future significant changes in ownership of the Company, as defined by the IRC.

6 unchanged sentences

The Company calculates basic and diluted net loss per share in conformity with the two-class method required for participating securities.

For the years ended December 31, 2023 and 2022, the Company had voting and non-voting common stock outstanding.

For the year ended December 31, 2023, the Company had voting and non-voting common stock outstanding.

In May 2024, 1,444,295 shares of non-voting common stock was converted to voting common stock and as of December 31, 2024, no shares of non-voting common stock remain outstanding.

Since the rights of the voting and non-voting common stock are identical, except with respect to voting, the undistributed losses of the Company have been allocated on a proportionate basis to the two classes.

Basic net loss per share of common stock is computed by dividing the net loss per share of common stock by the weighted average number of shares of common stock outstanding for the period.

The weighted-average shares of common stock outstanding as of December 31, 2023 and 2022 included outstanding pre-funded warrants to purchase up to an aggregate of 1,168,054 and 5,942,036 shares of common stock, respectively.

The weighted average shares of common stock outstanding as of December 31, 2023 included outstanding pre-funded warrants to purchase up to an aggregate of 1,168,054 shares of common stock.

No pre-funded warrants remain outstanding as of December 31, 2024.

Diluted net loss per share is calculated using the if-converted method, which assumes conversion of all non-voting common stock to voting common stock.

50 unchanged sentences

333-234017) filed on October 16, 2019 )

Amended and Restated Investors' Rights Agreement among the Registrant and certain of its stockholders, dated January 2, 2019 (incorporated by reference to Exhibit 4.2 of the Registrant’s Registration Statement on Form S-1 (File No.

333-234017) filed on September 30, 2019)

Description of Securities

Description of Securities (incorporated by reference to Exhibit 4.3 to the Registrant’s Annual Report on Form 10-K (File No.

001-39103) filed on March 21, 2024)

Form of Pre-Funded Warrant (incorporated by reference to Exhibit 4.1 of the Registrant's Current Report on Form 8-K (File No.

14 unchanged sentences

Form of Indemnification Agreement between the Registrant and each of its executive officers (incorporated by reference to Exhibit 10.4 of the Registrant’s Registration Statement on Form S-1, filed with the SEC on September 30, 2019)

to Exhibit 10.6 to the Registrant’s Registration Statement on Form S-1, filed with the SEC on September 30, 2019)

Sponsored Research Agreement, dated as of April 23, 2018, between the Registrant and the Trustees of the University of Pennsylvania (incorporated by reference to Exhibit 10.7 to the Registrant’s Registration Statement on Form S-1, filed with the SEC on September 30, 2019)

Sponsored Research Agreement, dated as of April 23, 2018, between the Registrant and the Trustees of the University of Pennsylvania (incorporated by reference to Exhibit 10.8 to the Registrant’s Registration Statement on Form S-1, filed with the SEC on September 30, 2019)

Amended and Restated License Agreement, dated as of July 23, 2019, among the Registrant, the Trustees of the University of Pennsylvania and the Children’s Hospital of Philadelphia (incorporated by reference to Exhibit 10.6 to the Registrant’s Registration Statement on Form S-1, filed with the SEC on September 30, 2019)

Master Translational Research Services Agreement, dated as of October 2018, between the Registrant and the Trustees of the University of Pennsylvania (incorporated by reference to Exhibit 10.9 to the Registrant’s Registration Statement on Form S-1, filed with the SEC on September 30, 2019)

7 unchanged sentences

Employment Agreement between the Registrant and David Chang (incorporated by reference to Exhibit 10.19 to the Registrant’s Registration Statement on Form S-1, filed with the SEC on September 30, 2019)

Third Amended and Restated Non-Employee Director Compensation Policy

Amendment No.

1, dated May 27, 2020, to the Sponsored Research Agreement, dated April 23, 2018, between the Registrant and the Trustees of the University of Pennsylvania (incorporated by reference to Exhibit 10.1 to the Registrant’s Current Report on Form 8-K (File No.

001-39103) filed on May 28, 2020)

Fourth Amended and Restated Non-Employee Director Compensation Policy

First Amendment, dated May 27, 2020, to the Amended and Restated License Agreement, dated July 23, 2019, among the Registrant, the Trustees of the University of Pennsylvania and the Children’s Hospital of Philadelphia (incorporated by reference to Exhibit 10.2 to the Registrant’s Current Report on Form 8-K (File No.

001-39103) filed on May 28, 2020)

Amendment to CAROT Master Services Addendum to Master Translational Research Services Agreement, dated as of May 18, 2020 between the Registrant and the Trustees of the University of

Pennsylvania (incorporated by reference to Exhibit 10.1 to the Registrant’s Quarterly Report on Form 10-Q (File No.

Amendment to CAROT Master Services Addendum to Master Translational Research Services Agreement, dated as of May 18, 2020 between the Registrant and the Trustees of the University of Pennsylvania (incorporated by reference to Exhibit 10.1 to the Registrant’s Quarterly Report on Form 10-Q (File No.

001-39103) filed on August 6, 2020)

Amendment No.

2, dated August 17, 2020, to the Sponsored Research Agreement, dated April 23, 2018, as amended by Amendment No.

1 dated May 27, 2020, between the Registrant and the Trustees of the University of Pennsylvania (incorporated by reference to Exhibit 10.1 to the Registrant’s Quarterly Report on Form 10-Q (File No.

001-39103) filed on November 10, 2020)

Amendment No.

1, dated April 27, 2021, to the Sponsored Research Agreement, dated April 23, 2018, between the Registrant and the Trustees of the University of Pennsylvania (incorporated by reference to Exhibit 10.1 to the Registrant’s Quarterly Report on Form 10-Q (File No.

001-39103) filed on May 3, 2021 )

Amendment No.

2, dated October 19, 2021, to the Sponsored Research Agreement, dated April 23, 2018, between the Registrant and the Trustees of the University of Pennsylvania (incorporated by reference to Exhibit 10.1 to the Registrant’s Quarterly Report on Form 10-Q (File No.

001-39103) filed on November 1, 2021 )

Second Amendment, dated October 19, 2021, to the First Amended and Restated License Agreement, dated May 27, 2020, among the Registrant, the Trustees of the University of Pennsylvania and the Children’s Hospital of Philadelphia (incorporated by reference to Exhibit 10.2 to the Registrant’s Quarterly Report on Form 10-Q (File No.

3 unchanged sentences

001-39103) filed on March 17, 2022)

Amendment No.

3, dated December 17, 2021, to the Sponsored Research Agreement, dated April 23, 2018, between the Registrant and the Trustees of the University of Pennsylvania (incorporated by reference to Exhibit 10.27 to the Registrant’s Annual Report on Form 10-K (File No.

001-39103) filed on March 17, 2022)

Amendment No.

4, dated December 1, 2022, to the Sponsored Research Agreement, dated April 23, 2018, between the Registrant and the Trustees of the University of Pennsylvania (incorporated by reference to Exhibit 10.33 to the Registrant’s Annual Report on Form 10-K (File No.

001-39103) filed on March 16, 2023)

Amendment No.

5, dated July 25, 2023, to the Sponsored Research Agreement, dated April 23, 2018, between the Registrant and the Trustees of the University of Pennsylvania (incorporated by reference to Exhibit 10.2 to the Registrant’s Quarterly Report on Form 10-Q (File No.

001-39103) filed on November 9, 2023)

Form of Employment Agreement (incorporated by reference to Exhibit 10.28 to the Registrant’s Annual Report on Form 10-K (File No.

001-39103) filed on March 17, 2022)

Sponsored Research Agreement, dated as of December 23, 2021, between the Registrant and the Trustees of the University of Pennsylvania (incorporated by reference to Exhibit 10.29 to the Registrant’s Annual Report on Form 10-K (File No.

001-39103) filed on March 17, 2022)

Option Agreement, dated December 23, 2021, by and between the Registrant and the Trustees of the University of Pennsylvania (incorporated by reference to Exhibit 10.30 to the Registrant’s Annual Report on Form 10-K (File No.

8 unchanged sentences

001-39103) filed on November 10, 2022 )

Development, Manufacturing, and Testing Services Agreement, dated January 11, 2021, between the Registrant and WuXi Advanced Therapies Inc.(incorporated by reference to Exhibit 10.34 to the Registrant’s Annual Report on Form 10-K (File No.

Development, Manufacturing, and Testing Services Agreement, dated January 11, 2021, between the Registrant and WuXi Advanced Therapies Inc.

(incorporated by reference to Exhibit 10.34 to the Registrant’s Annual Report on Form 10-K (File No.

001-39103) filed on March 16, 2023)

1 unchanged sentence

001-39103) filed on May 11, 2023)

Third Amendment to the Licence and Supply Agreement, dated as of February 21, 2024, between the Registrant and Oxford Biomedica (UK) Limited (incorporated by reference to Exhibit 10.1 to the Registrant's Quarterly Report on Form 10-Q (File No.

001-39103) filed on May 15, 2024)

Fourth Amendment to the Licence and Supply Agreement, dated as of June 24, 2024, between the Registrant and Oxford Biomedica (UK) Limited (incorporated by reference to Exhibit 10.1 to the Registrant's Quarterly Report on Form 10-Q (File No.

001-39103) filed on August 8, 2024)

Services Agreement, dated as of February 1, 2019, between the Registrant and CIC Innovation Communities, LLC (incorporated by reference to Exhibit 10.1 to the Registrant's Quarterly Report on Form 10-Q (File No.

001-39103) filed on November 14, 2024)

Amendment to the Services Agreement, dated as of December 1, 2021, between the Registrant and CIC Innovation Communities, LLC (incorporated by reference to Exhibit 10.2 to the Registrant's Quarterly Report on Form 10-Q (File No.

001-39103) filed on November 14, 2024)

Amendment to the Services Agreement, dated as of September 30, 2024, between the Registrant and CIC Innovation Communities, LLC (incorporated by reference to Exhibit 10.3 to the Registrant's Quarterly Report on Form 10-Q (File No.

001-39103) filed on November 14, 2024)

Second Amendment, dated September 24, 2024, to the Lease, dated as of February 11, 2019, between the Registrant and Brandywine Cira, L.P., as amended.

(incorporated by reference to Exhibit 10.4 to the Registrant's Quarterly Report on Form 10-Q (File No.

001-39103) filed on November 14, 2024)

Insider Trading Policy

List of Subsidiaries of the Registrant

8 unchanged sentences

Section 1350, as adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

Cabaletta Bio, Inc.'s Compensation Recovery Policy

Cabaletta Bio, Inc.'s Compensation Recovery Policy (incorporated by reference to Exhibit 99.7 to the Registrant's Annual Report on Form 10-K (File No.

001-39103) filed on March 21, 2024)

Inline XBRL Instance Document – the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document

41 unchanged sentences

Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-K

Item 9A. Controls and Procedures