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Item 9A. Controls and Procedures

2025-03-27 compared with 2024-03-13 · 47 added, 880 removed, 167 unchanged (85% of the section changed)

1 unchanged sentence

Evaluation of Disclosure Controls and Procedures

Our management, with the participation of our Chief Executive Officer and Chief Financial Officer (our principal executive officer and principal financial officer, respectively), evaluated the effectiveness of our disclosure controls and procedures as of December 31, 2023.

Our management, with the participation of our Interim Chief Executive Officer and Chief Financial Officer (our principal executive officer and principal financial officer) evaluated the effectiveness of our disclosure controls and procedures as of December 31, 2024.

The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), means controls and other procedures of a company that are designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported, within the time periods specified in the SEC’s rules and forms.

1 unchanged sentence

Management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving their objectives and management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures.

Based on the evaluation of our disclosure controls and procedures as of December 31, 2023, our Chief Executive Officer and Chief Financial Officer concluded that, as of such date, our disclosure controls and procedures were effective at the reasonable assurance level.

Based on the evaluation of our disclosure controls and procedures as of December 31, 2024, our Interim Chief Executive Officer and Chief Financial Officer concluded that, as of such date, our disclosure controls and procedures were effective at the reasonable assurance level.

Management’s Annual Report on Internal Controls Over Financial Reporting

8 unchanged sentences

Other Information.

Trading Arrangements

None of our directors or officers adopted or terminated a Rule 10b5-1 trading arrangement or a non-Rule 10b5-1 trading arrangement (as defined in Item 408(c) of Regulation S-K) during fiscal year 2024.

Disclosure Regarding Foreign Jurisdictions that Prevent Inspections.

1 unchanged sentence

Directors, Executive Officers and Corporate Governance.

Set forth below are the names of our directors as of March 8, 2024, their ages, their offices, if any, their principal occupations or employment for at least the past five years, the length of their tenure as directors and the names of other public companies in which such persons hold or have held directorships during the past five years.

Additionally, information about the specific experience, qualifications, attributes or skills that led to our Board of Directors’ conclusion that each person listed below should serve as a director is set forth below:

Position with the Company

Milind Deshpande, Ph.D.

Scott Jackson

Ankit Mahadevia, M.D.

Pottage, Jr., M.D.

Satyavrat Shukla

Chief Executive Officer, President and Director

Cynthia Smith

Kathleen Tregoning

Patrick Vink, M.D.

Lead Director

Our Board of Directors has reviewed the materiality of any relationship that each of our directors has with Spero Therapeutics, Inc., either directly or indirectly.

Based upon this review, our Board of Directors has determined that the following members of the Board of Directors are “independent directors” as defined by The Nasdaq Stock Market:

Milind Deshpande, Ph.D., Scott Jackson, John C.

Pottage, Jr., M.D., Cynthia Smith, Frank E.

Thomas, Kathleen Tregoning and Patrick Vink, M.D.

See “Item 13.

Certain Relationships and Related Transactions, and Director Independence.”

Milind Deshpande, Ph.D.

has served on our Board of Directors since January 2014 and previously served as Chairman of our Board of Directors from January 2014 to August 2023.

Deshpande is the President and Chief Executive Officer at Nayan Therapeutics since February 2019, and previously served as President and Chief Executive Officer of Avilar Therapeutics from January 2020 to June 2021.

He is also a Venture Partner at RA Capital, where he has served since October 2018.

Deshpande served as President and Chief Executive Officer of Achillion Pharmaceuticals, Inc.

and served on the board of directors from May 2013 until May 2018.

He joined Achillion in September 2001 as Vice President of Chemistry, was named Head of Drug Discovery in April 2002, Senior Vice President of Drug Discovery in December 2002, Senior Vice President and Chief Scientific Officer in December 2004, Executive Vice President of Research and Chief Scientific Officer in June 2007 and President of Research and Development in October 2010.

Prior to joining Achillion, Dr.

Deshpande was Associate Director of Lead Discovery and Early Discovery Chemistry at the Pharmaceutical Research Institute at Bristol-Myers Squibb Co.

from 1991 to 2001, where he managed the identification of new clinical candidates to treat infectious and neurological diseases.

From 1988 to 1991, he held a faculty position at Boston University Medical School.

Deshpande currently serves as the chairman of the board of directors of Avilar Therapeutics and as a member of the board of directors of Triana Biomedicines and Clear Creek Bio.

Deshpande received his Ph.D.

in Organic Chemistry from Ohio University, following his undergraduate education in India.

We believe that Dr.

Deshpande is qualified to serve on our Board of Directors due to his extensive experience in the life sciences industry.

Scott Jackson has served on our Board of Directors since April 2020.

Jackson served as Chief Executive Officer and as a member of the board of directors of Celator Pharmaceuticals, Inc.

from April 2008 until July 2016, when the company was acquired by Jazz Pharmaceuticals plc.

Jackson has more than thirty years of corporate leadership experience in the pharmaceutical and biotechnology industry and has held positions of increasing responsibility in sales, marketing and commercial development at Eli Lilly & Company, SmithKline Beecham plc, ImClone Systems Incorporated, Centocor Inc., a division of Johnson & Johnson, Eximias Pharmaceutical Corporation and YM BioSciences Inc.

Jackson presently serves on the boards of Philabundance Food Bank, MacroGenics, Inc.

and GlycoMimetics, Inc.

Jackson holds a B.S.

in pharmacy from the Philadelphia College of Pharmacy and Science and an M.B.A.

from the University of Notre Dame.

We believe that Mr.

Jackson’s extensive executive leadership experience in the pharmaceutical industry and his experience as a member of the board of directors of other publicly traded biotechnology companies, as well as his broad life sciences industry knowledge qualifies him to serve on our Board of Directors.

Ankit Mahadevia, M.D.

has been a member of our Board of Directors since September 2013 and currently serves as Chairman of our Board of Directors, a position he has held since August 2023.

Mahadevia formerly served as our Chief Executive Officer and President from March 2015 until August 2023.

He was formerly a Venture Partner in the life sciences group at Atlas Venture, located in Cambridge, Massachusetts.

In that capacity, he supported the formation of eight companies focused on novel drug

discovery platforms and therapeutic products, including Nimbus Therapeutics, Arteaus Therapeutics (acquired by Lilly), and Translate Bio (Nasdaq:

He led three of these companies as acting chief executive officer, including Synlogic (Nasdaq:

Prior to joining Atlas Venture in 2008, Dr.

Mahadevia worked on product and business development with the founding team at Arcion Therapeutics, Inc.

He has also held positions in business development both at Genentech, Inc.

and at Vanda Pharmaceuticals Inc.

Previously, he worked in the health care groups of McKinsey & Company and Monitor Group.

Mahadevia began his career in health care policy, with roles in the U.S.

Senate Health, Education, Labor, and Pensions committees, the U.S.

Government Accountability Office and the Mexican Institute of Social Security.

He has spoken widely on entrepreneurship, including at Harvard University, Columbia University, Northwestern University, and the Berkeley Forum.

Mahadevia has also been active in the policy of life science innovation, including service on the Advisory Council at the NIH National Center for Advancing Translational Sciences.

Mahadevia holds an M.D.

from the Johns Hopkins School of Medicine, an M.B.A.

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

in Economics and Biology from Northwestern University.

We believe that Dr.

Mahadevia is qualified to serve on our Board of Directors due to his experience serving as our Chief Executive Officer and President and his extensive experience in the life sciences industry.

Pottage, Jr., M.D.

has served on our Board of Directors since September 2018.

Pottage served as Senior Vice President and Chief Scientific and Medical Officer of ViiV Healthcare from November 2009 to October 2019.

From September 2008 to November 2009, Dr.

Pottage served as Senior Vice President, Head of Infectious Disease Medicine Development Center and, from June 2007 to September 2008, as the Vice President, Global Clinical Development of Antivirals, at GlaxoSmithKline.

Prior to joining GlaxoSmithKline, Dr.

Pottage served as Chief Medical Officer and Senior Vice President of Drug Development of Achillion Pharmaceuticals from May 2002 to May 2007.

From July 1998 to May 2002, Dr.

Pottage served as Medical Director of Vertex Pharmaceuticals (Nasdaq:

VRTX) (“Vertex”).

Pottage currently serves on the board of directors of Pardes Biosciences, Inc.

We believe that Dr.

Pottage’s extensive industry and executive experience, his broad experience within the biopharmaceutical sector and his knowledge of the life sciences industry qualifies him to serve on our Board of Directors.

Satyavrat Shukla has served as our Chief Executive Officer and President since August 2023 and has been a member of our Board of Directors since August 2023.

He previously served as our Chief Financial Officer and Treasurer from January 2021 to August 2023.

He has over 20 years of strategic and financial leadership experience.

He was most recently Chief Financial Officer at Ziopharm Oncology, Inc.

from July 2019 to December 2020, where he directed all of Ziopharm’s financial aspects, including financial planning, analysis and reporting, treasury and tax functions, capital strategy and investor relations.

Prior to Ziopharm, Mr.

Shukla was Vice President and Global Head of Corporate Finance for Vertex.

from July 2012 to July 2019, where he managed financial planning, analysis and budgeting, and led the annual long-range planning process encompassing Vertex’s entire portfolio and operations across more than 30 countries.

Previously, Mr.

Shukla was a Principal at Cornerstone Research, where he led teams providing consulting services for life science clients ranging from start-ups to multi-billion-dollar corporations.

Prior to Cornerstone, he worked for finance consulting firms LECG Corporation and Putnam, Hayes & Bartlett, Inc.

Shukla earned a B.A.

in Economics from Harvard University and an M.B.A.

in Finance and Strategy from Yale University.

He also holds the Chartered Financial Analyst designation.

Cynthia Smith has served on our Board of Directors since March 2019.

Smith was Chief Commercial Officer of ZS Pharma, from June 2013 to December 2016.

ZS Pharma became a subsidiary of AstraZeneca after its acquisition in December 2015.

Prior to joining ZS Pharma, Ms.

Smith was Vice President, Market Access & Commercial Development at Affymax, Inc., a biotechnology company focused on the development and commercialization of novel renal therapies, including a new anemia drug for chronic kidney disease patients.

Smith was employed at Affymax from October 2008 to March 2013.

Prior to Affymax, Ms.

Smith was Executive Director of Healthcare Systems and Medicare Strategy at Merck.

During her tenure at Merck from June 2000 to October 2008, she also held various leadership positions in corporate strategy, public policy, and external affairs, including global crisis management for the Vioxx recall.

Before joining the pharmaceutical industry, she served in the White House Office of Management and Budget (OMB) in the Clinton Administration.

Smith earned an M.B.A.

from the Wharton School of the University of Pennsylvania, an MS in public policy from the Eagleton Institute of Politics at Rutgers University, and a BA from the University of North Carolina at Chapel Hill.

Smith also serves on the boards of directors of Agios Pharmaceuticals, Akebia Therapeutics and Protara Therapeutics, Inc.

We believe that Ms.

Smith’s extensive management experience in the healthcare industry and her experience as a member of the board of directors of other publicly traded biotechnology companies, as well as her broad life sciences industry knowledge, qualifies her to serve on our Board of Directors.

Thomas has served on our Board of Directors since July 2017.

Thomas is currently President and Chief Operating Officer of Orchard Therapeutics, a development-stage biotechnology company based in the United Kingdom, where he served as Chief Financial Officer and Chief Business Officer from January 2018 to March 2020.

Prior to Orchard, Mr.

Thomas served as the President and Chief Operating Officer of AMAG Pharmaceuticals, Inc., a commercial-stage pharmaceutical company, which was a publicly traded company that was subsequently acquired by Covis Pharmaceuticals, Inc., from April 2015 to April 2017, as AMAG’s Executive Vice President and Chief Operating Officer from May 2012 through April 2015 and as Executive Vice President, Chief Financial Officer and Treasurer from August 2011 through May 2012.

Prior to AMAG, he served as Senior Vice President, Chief Operating Officer and Chief Financial Officer for Molecular Biometrics, Inc., a commercial-stage medical diagnostics company,

from October 2008 to July 2011.

Prior to Molecular Biometrics, Mr.

Thomas spent four years at Critical Therapeutics, Inc., which was a publicly traded company that subsequently merged with Cornerstone Therapeutics Inc., from April 2004 to March 2008, where he was promoted to President in June 2006 and Chief Executive Officer in December 2006 from the position of Senior Vice President and Chief Financial Officer.

He also served on the board of directors of Critical Therapeutics from 2006 to 2008.

Prior to 2004, Mr.

Thomas served as the Chief Financial Officer and Vice President of Finance and Investor Relations at Esperion Therapeutics, Inc., a public biopharmaceutical company (Nasdaq:

Thomas was a member of the board of directors of the Massachusetts Biotechnology Council from 2007 to 2015.

Thomas currently serves as a member of the board of directors of Larimar Therapeutics Inc (Nasdaq:

Thomas holds a B.B.A.

from the University of Michigan, Ann Arbor.

We believe that Mr.

Thomas’ extensive commercial and operational management experience at biopharmaceutical companies and with financial matters qualifies him to serve on our Board of Directors.

Kathleen Tregoning has served on our Board of Directors since October 2021.

Tregoning has served as Chief Corporate Affairs Officer of Cerevel Therapeutics Holdings, Inc.

since July 2020.

Previously, from February 2017 to March 2020, Ms.

Tregoning served as Executive Vice President for External Affairs at Sanofi S.A., a French multinational pharmaceutical company, where she was responsible for leading an integrated organization that brought together market access, communications, public policy, government affairs, patient advocacy and corporate social responsibility.

Prior to joining Sanofi, Ms.

Tregoning spent more than a decade at Biogen Inc., a multinational biotechnology company, first as Vice President, Public Policy & Government Affairs, from 2006 to 2015, and then as Senior Vice President, Corporate Affairs, from December 2015 to February 2017.

Previously, Ms.

Tregoning served as a professional staff member in the United States Congress, where she held health policy roles with the Senate Budget Committee, the House Energy & Commerce Committee, and the House Ways & Means Committee.

Tregoning began her career with Andersen Consulting, where she developed business strategies and processes for clients in a range of industries, and later served as an Assistant Deputy Mayor for Policy & Budget in the office of the Mayor of Los Angeles.

Tregoning graduated from Stanford University with a B.A.

in International Relations and holds an M.A.

in Public Policy from the Kennedy School of Government at Harvard University.

We believe that Ms.

Tregoning is qualified to serve on our Board of Directors because of her senior and executive leadership experience in several biopharmaceutical companies.

Patrick Vink, M.D.

has served on our Board of Directors since September 2015 and currently serves as our Lead Director, a position he has held since August 2023.

Vink has been an advisor to the pharmaceutical industry since 2015 and board member of several companies.

Previously, Dr.

Vink was employed at Cubist Pharmaceuticals, Inc.

Most recently, he served as Executive Vice-President and Chief Operating Officer, overseeing all worldwide commercial and technical operations as well as global alliance management and managing the company’s profit and loss.

He joined Cubist in 2012 as Senior Vice President and Head of all International Business Operations.

In this role, he was responsible for the business activities in international markets outside USA.

Prior to joining Cubist, Dr.

Vink served as Senior Vice President, Global Head of Hospital Business and Global Head of Biologics for Mylan Inc.

In this role, Dr.

Vink managed the global hospital business of the company.

He joined Mylan in 2008 and established a number of global functions for the company in Switzerland.

Before joining Mylan, Dr.

Vink held several leadership positions across the industry, including Head of Global Business Franchise Biopharmaceuticals for Novartis Sandoz;

Vice President International Business for Biogen, Inc.;

and Head of Worldwide Marketing, Cardiovascular and Thrombosis for Sanofi-Synthélabo SA.

Vink served as a member of the Executive Committee of the European Federation of Pharmaceutical Industries and Associations (EFPIA) between 2013 and 2015.

Vink graduated as a medical doctor from the University of Leiden, Netherlands in 1988 and obtained his M.B.A.

in 1992 from the University of Rochester.

Vink serves on the boards of directors of Santhera Pharmaceuticals AG, Amryt Pharma PLC., and is chairman of the board of directors of two privately held companies.

We believe that Dr.

Vink is qualified to serve on our Board of Directors because of his extensive operational business experience, significant knowledge of the activities of our company, and diverse background serving on the board of directors of various public and private life science companies.

Term of Office of Directors

Our Amended and Restated Bylaws provide that our business is to be managed by or under the direction of our Board of Directors.

Our Board of Directors is divided into three classes for purposes of election.

One class is elected at each annual meeting of stockholders to serve for a three-year term.

Our Board of Directors currently consists of eight members, classified into three classes as follows:

Cynthia Smith, Scott Jackson and John C.

Pottage, Jr., M.D.

constitute our Class I directors with a term ending at the 2024 annual meeting of stockholders;

Patrick Vink, M.D., Frank E.

Thomas and Satyavrat Shukla constitute our Class II directors with a term ending at the 2025 annual meeting of stockholders;

Milind Deshpande, Ph.D., Ankit Mahadevia, M.D.

and Kathleen Tregoning constitute our Class III directors with a term ending at the 2026 annual meeting of stockholders.

Committees of the Board of Directors and Meetings

Meeting Attendance.

During the fiscal year ended December 31, 2023, there were five meetings of our Board of Directors, and the various committees of the Board of Directors met a total of 12 times.

No director attended fewer than 75% of the total number of meetings of the Board of Directors and of committees of the Board of Directors on which such director served during the fiscal year ended December 31, 2023.

The Board of Directors has adopted a policy under which each member of the Board of Directors makes every effort to but is not required to attend each annual meeting of our stockholders.

Audit Committee.

Our Audit Committee met six times during the fiscal year ended December 31, 2023.

This committee currently has three members, Frank E.

Thomas (Chair), Scott Jackson and John C.

Pottage, Jr., M.D.

During the period of January 1, 2023 through September 15, 2023, our Audit Committee consisted of Mr.

Thomas (Chair), Mr.

Pottage, and Dr.

Our Audit Committee’s role and responsibilities are set forth in the Audit Committee’s written charter and include the authority to retain and terminate the services of our independent registered public accounting firm.

In addition, the Audit Committee reviews annual financial statements, considers matters relating to accounting policy and internal controls and reviews the scope of annual audits.

All members of the Audit Committee satisfy the current independence standards promulgated by the SEC and by The Nasdaq Stock Market, as such standards apply specifically to members of audit committees.

The Board of Directors has determined that Mr.

Thomas is an “audit committee financial expert,” as the SEC has defined that term in Item 407 of Regulation S-K.

Please also see the report of the Audit Committee set forth elsewhere in this proxy statement.

A copy of the Audit Committee’s written charter is publicly available on our website at www.sperotherapeutics.com.

Compensation Committee.

Our Compensation Committee met four times during the fiscal year ended December 31, 2023.

This committee currently has three members, Cynthia Smith (Chair), Patrick Vink, M.D., and Kathleen Tregoning.

During the period of January 1, 2023 through September 15, 2023, our Compensation Committee consisted of Dr.

Vink (Chair), Dr.

Deshpande, Ms.

Smith, and Ms.

Our Compensation Committee’s role and responsibilities are set forth in the Compensation Committee’s written charter and include reviewing, approving and making recommendations regarding our compensation policies, practices and procedures to ensure that legal and fiduciary responsibilities of the Board of Directors are carried out and that such policies, practices and procedures contribute to our success.

Our Compensation Committee also administers the Spero Therapeutics, Inc.

2017 Stock Incentive Plan, as amended (the “2017 Plan”), and our 2019 Inducement Equity Incentive Plan, as amended (the “2019 Inducement Plan”).

The Compensation Committee is responsible for the determination of the compensation of our chief executive officer and shall conduct its decision-making process with respect to that issue without the chief executive officer present.

All members of the Compensation Committee qualify as independent under the definition promulgated by The Nasdaq Stock Market

The Compensation Committee retains Meridian Compensation Partners, LLC (“Meridian”) as an independent advisor to the Compensation Committee to provide executive compensation consulting services.

Meridian did not provide any services to us other than executive compensation consulting services during the fiscal year ended December 31, 2023.

In compliance with the SEC and the corporate governance rules of The Nasdaq Stock Market, Meridian provided the Compensation Committee with a letter addressing each of the six independence factors.

Their responses affirm the independence of Meridian and the partners, consultants, and employees who service the Compensation Committee on executive compensation matters and governance issues.

A copy of the Compensation Committee’s written charter is publicly available on our website at www.sperotherapeutics.com.

Nominating and Corporate Governance Committee .

Our Nominating and Corporate Governance Committee (“Nominating Committee”) met two times during the fiscal year ended December 31, 2023 and has three members, Patrick Vink, M.D.

(Chair), Milind Deshpande, Ph.D., and Scott Jackson.

During the period of January 1, 2023 through September 15, 2023, our Nominating Committee consisted of Dr.

Deshpande (Chair), Mr.

Our Board of Directors has determined that all members of the Nominating Committee qualify as independent under the definition promulgated by The Nasdaq Stock Market.

The Nominating Committee’s responsibilities are set forth in the Nominating Committee’s written charter and include:

• identifying and recommending candidates for membership on our Board of Directors;

• recommending directors to serve on board committees;

• reviewing and recommending our corporate governance guidelines and policies;

• reviewing proposed waivers of the code of conduct for directors and executive officers;

• evaluating, and overseeing the process of evaluating, the performance of our Board of Directors and individual directors;

• assisting our Board of Directors on corporate governance matters.

Generally, our Nominating Committee considers candidates recommended by stockholders as well as from other sources such as other directors or officers, third party search firms or other appropriate sources.

Once identified, the Nominating Committee will evaluate a candidate’s qualifications in accordance with the criteria set forth in our Corporate Governance Guidelines.

Our Nominating Committee has not adopted a formal diversity policy in connection with the consideration of director nominations or the selection of nominees.

However, the Nominating Committee will consider issues of diversity among its members in identifying and considering nominees for director, and strive where appropriate to achieve a diverse balance of backgrounds, perspectives, experience, age, gender, ethnicity and country of citizenship on the Board of Directors and its committees.

If a stockholder wishes to propose a candidate for consideration as a nominee for election to the Board of Directors, it must follow the procedures described in our Amended and Restated Bylaws and in “Stockholder Proposals and Nominations For Director” at the end of this proxy statement.

Any such recommendation should be made in writing to the Nominating and Governance Committee, care of our Secretary at our principal office and should be accompanied by the following information concerning each recommending stockholder and the beneficial owner, if any, on whose behalf the nomination is made:

• all information relating to such person that would be required to be disclosed in a proxy statement;

• certain biographical and share ownership information about the stockholder and any other proponent, including a description of any derivative transactions in our securities;

• a description of certain arrangements and understandings between the proposing stockholder and any beneficial owner and any other person in connection with such stockholder nomination;

• a statement whether or not either such stockholder or beneficial owner intends to deliver a proxy statement and form of proxy to holders of voting shares sufficient to carry the proposal.

The recommendation must also be accompanied by the following information concerning the proposed nominee:

• certain biographical information concerning the proposed nominee;

• all information concerning the proposed nominee required to be disclosed in solicitations of proxies for election of directors;

• certain information about any other security holder who supports the proposed nominee;

• a description of all relationships between the proposed nominee and the recommending stockholder or any beneficial owner, including any agreements or understandings regarding the nomination;

• additional disclosures relating to stockholder nominees for directors, including completed questionnaires and disclosures required by our Amended and Restated Bylaws.

Development Committee .

Our Development Committee met one time during the fiscal year ended December 31, 2023 and has three members, John C.

Pottage, Jr., M.D.

(Chair), Milind Deshpande, Ph.D., and Ankit Mahadevia, M.D.

Our Development Committee provides additional Board of Directors oversight and engagement with respect to the ongoing development of our product candidates and our research and development programs.

Corporate Governance Guidelines.

Our Board of Directors has adopted corporate governance guidelines, which apply to our principal executive officer, our principal financial and accounting officer and all of our other employees, to assist in the exercise of its duties and responsibilities and to serve the best interests of us and our stockholders.

The guidelines provide that:

• our Board of Directors’ principal responsibility is to oversee our management;

• except as required by Nasdaq rules, a majority of the members of our Board of Directors must be independent directors;

• the independent directors meet in executive session at least twice a year;

• directors have full and free access to management and, as necessary, independent advisors;

• our nominating and corporate governance committee will oversee periodic self-evaluations of the Board of Directors to determine whether it and its committees are functioning effectively.

While we have no formal policy regarding diversity of our board members, our Corporate Governance Guidelines provide that the background and qualifications of the members of our Board of Directors considered as a group should provide a significant breadth of experience, knowledge, and ability to assist our Board of Directors in fulfilling its responsibilities.

Our priority in selection

of board members is the identification of members who will further the interests of our stockholders through their established records of professional accomplishment, the ability to contribute positively to the collaborative culture among our board members, knowledge of our business, understanding of the competitive landscape in which we operate and adherence to high ethical standards.

Copies of the Nominating Committee’s written charter and our Corporate Governance Guidelines are publicly available on our website at www.sperotherapeutics.com.

Code of Business Conduct and Ethics.

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

The text of the Code of Business Conduct and Ethics is posted on our website at www.sperotherapeutics.com and will be made available to stockholders without charge, upon request, in writing to our Secretary at Spero Therapeutics, Inc., 675 Massachusetts Avenue, 14th Floor, Cambridge, Massachusetts 02139.

Disclosure regarding any amendments to, or waivers from, provisions of the Code of Business Conduct and Ethics that apply to our directors, principal executive and financial officers will be included in a Current Report on Form 8-K within four business days following the date of the amendment or waiver, unless website posting or the issuance of a press release of such amendments or waivers is then permitted by the rules of The Nasdaq Stock Market.

Compensation Committee Interlocks and Insider Participation.

None of the members of our Compensation Committee has at any time during the prior three years been one of our officers or employees.

None of our executive officers currently serves, or in the past fiscal year has served, as a member of our Board of Directors or Compensation Committee of any entity that has one or more executive officers serving on our Board of Directors or Compensation Committee.

For a description of transactions between us and members of our Compensation Committee and affiliates of such members, see “Certain Relationships and Related Person Transactions.”

Board Leadership Structure and Role in Risk Oversight

Our Board of Directors is currently chaired by Ankit Mahadevia, M.D.

As a general policy, our Board of Directors believes that separation of the positions of Chairman and Chief Executive Officer reinforces the independence of our Board of Directors from management, creates an environment that encourages objective oversight of management’s performance and enhances the effectiveness of our Board of Directors as a whole.

Shukla serves as our Chief Executive Officer, while Dr.

Mahadevia serves as the Chairman of our Board of Directors but is not an officer and Patrick Vink, M.D.

serves as Lead Director as he is an “independent” director.

Our Board of Directors oversees the management of risks inherent in the operation of our business and the implementation of our business strategies.

Our Board of Directors performs this oversight role by using several different levels of review.

In connection with its reviews of our operations and corporate functions, our Board of Directors addresses the primary risks associated with those operations and corporate functions.

In addition, our Board of Directors reviews the risks associated with our business strategies periodically throughout the year as part of its consideration of undertaking any such business strategies.

Each of our board committees also oversees the management of our risk that falls within the committee’s areas of responsibility.

In performing this function, each committee has full access to management, as well as the ability to engage advisors.

Our Chief Executive Officer reports to the Audit Committee and is responsible for identifying, evaluating and implementing risk management controls and methodologies to address any identified risks.

In connection with its risk management role, our Audit Committee meets privately with representatives from our independent registered public accounting firm and our Chief Executive Officer.

The Audit Committee oversees the operation of our risk management program, including the identification of the primary risks associated with our business and periodic updates to such risks, and reports to our Board of Directors regarding these activities.

Stockholder Communications to the Board of Directors

Generally, stockholders who have questions or concerns should contact our Investor Relations department at 857-242-1547 or ir@sperotherapeutics.com.

However, any stockholders who wish to address questions regarding our business directly with the Board of Directors, or any individual director, should direct his or her questions in writing to the Chairman of the Board of Directors at Spero Therapeutics, Inc., 675 Massachusetts Avenue, 14th Floor, Cambridge, Massachusetts 02139.

Communications will be distributed to the Board of Directors, or to any individual director or directors as appropriate, depending on the facts and circumstances outlined in the communications.

Items that are unrelated to the duties and responsibilities of the Board of Directors may be excluded, such as:

junk mail and mass mailings;

resumes and other forms of job inquiries;

and solicitations or advertisements.

In addition, any material that is unduly hostile, threatening, or illegal in nature may be excluded, provided that any communication that is filtered out will be made available to any outside director upon request.

Executive Officers

The following table sets forth certain information regarding our executive officers who are not also directors as of March 8, 2024.

We have employment agreements or consulting agreements with each of our executive officers.

Kamal Hamed, M.D.

Chief Medical Officer

Timothy Keutzer

Chief Operating Officer

Esther Rajavelu

Chief Financial Officer and Chief Business Officer

Kamal Hamed, M.D.

has served as our Chief Medical Officer since September 2022.

Hamed has over 20 years of experience leading various anti-infective clinical development programs in antibacterials, antivirals, antimalarials, and antifungals.

Before joining us, he was the CMO at Lysovant Sciences, a subsidiary of Roivant Sciences.

Prior to his time at Lysovant, Dr.

Hamed was Head of Clinical Development & Medical Affairs at Basilea Pharmaceutica.

Earlier in his career, he held senior positions in clinical development and medical affairs at Novartis (including Therapeutic Area Head for Anti-infectives), Bristol-Myers Squibb, and Bayer, spearheading the successful global development, approval, and post-marketing medical affairs support of multiple anti-infective products.

Prior to joining the pharmaceutical industry, Dr.

Hamed worked as an academic physician for 14 years.

He holds an M.D.

degree from the American University of Beirut, an M.P.H.

degree from Johns Hopkins University, and an M.B.A.

degree from the University of South Florida.

Hamed completed a residency in Internal Medicine at UMDNJ–Robert Wood Johnson Medical School and a fellowship in Infectious Diseases at Stanford University School of Medicine.

He is a fellow of both the American College of Physicians and the Infectious Diseases Society of America and has published over 120 manuscripts in peer-reviewed journals.

Timothy Keutzer has served as our Chief Operating Officer since February 2023 and previously served as our Chief Development Officer from June 2019 until February 2023 and as our Senior Vice President, Development from September 2015 to June 2019.

He has over 20 years’ experience in the pharmaceutical industry, spanning multiple functional and therapeutic areas.

Prior to joining Spero, Mr.

Keutzer served in various roles at Cubist Pharmaceuticals, including Vice President of Program and Portfolio Management from May 2014 to July 2015.

At Cubist Mr.

Keutzer was the program leader for ceftolozane/tazobactam, which progressed rapidly from Phase 1 to Phase 3, and was approved in the FDA in December of 2014.

Prior to that role, he also led several of Cubist’s inlicensed development programs, and also led the commercial supply chain for Cubicin.

His experience before Cubist spans multiple drug classes and includes preclinical PK/PD and clinical operations at Genetics Institute, as well as global strategic marketing and program management at Wyeth.

Tim began his career in contract toxicology labs.

Keutzer earned his bachelor’s degree from the University of Kentucky.

Esther Rajavelu has served as our Chief Financial Officer and Chief Business Officer since November 2023.

Rajavelu most recently served as Chief Financial Officer of Fulcrum Therapeutics, Inc.

(“Fulcrum”) from January 2022 to April 2023.

Prior to joining Fulcrum, Ms.

Rajavelu’s career in the biotechnology sector includes her time as an equities research analyst, investment banker, and strategy consultant.

She served as a senior equities research analyst at UBS Securities ("UBS”) from July 2020 to December 2021.

Prior to joining UBS, Ms.

Rajavelu served as a senior equities research analyst at Oppenheimer & Co.

("Oppenheimer”) from June 2018 to July 2020.

Prior to joining Oppenheimer, Ms.

Rajavelu served as an equities research analyst at Deutsche Bank from June 2014 to June 2018.

Prior to joining Deutsche Bank, she served as vice president, life sciences M&A and capital & debt advisory at Ernst & Young Capital Advisors, LLC ("EY Capital Advisors”) from 2011 to 2014.

Prior to joining EY Capital Advisors, she worked at Bank of America Merrill Lynch from 2006 to 2011 in the healthcare investment banking group where she focused on financing and strategic transactions in the biotechnology and medical devices sectors.

Rajavelu received a MBA from The Wharton School of the University of Pennsylvania and a B.A.

in Economics and International Relations from Wesleyan University

Director or Officer Involvement in Certain Legal Proceedings

Our directors and executive officers have not been involved in any legal proceedings as described in Item 401(f) of Regulation S-K in the past ten years.

The response to this item is incorporated by reference from the discussion responsive thereto under the captions “Management and Corporate Governance Matters” and “Code of Conduct and Ethics” in the Company’s proxy statement for the 2025 Annual Meeting of Stockholders to be filed with the SEC within 120 days after the end of the fiscal year covered by this Annual Report on Form 10-K.

Executive Compensation.

The following table shows the total compensation paid or accrued during the last two fiscal years ended December 31, 2023 and 2022 to our current President and Chief Executive Officer, our former President and Chief Executive Officer, and our two next most highly compensated executive officers who earned more than $100,000 during the fiscal year ended December 31, 2023 and were serving as executive officers as of such date (the “named executive officers”).

Name and Principal Position

Incentive Plan

Satyavrat Shukla

Chief Executive Officer and President

Ankit Mahadevia, M.D.

Former Chief Executive Officer and President (6)

Tamara Joseph

Former Chief Legal Officer (7)

Timothy Keutzer

Chief Operating Officer

Consists of retention bonuses paid to Mr.

Mahadevia, Ms.

Joseph and Mr.

Keutzer during the years ended December 31, 2023 and 2022.

These amounts represent the aggregate grant date fair value for RSU awards computed in accordance with ASC 718.

A discussion of the assumptions used in determining grant date fair value may be found in Note 8 to our consolidated financial statements for the year ended December 31, 2023.

These amounts represent the aggregate grant date fair value for option awards computed in accordance with ASC 718.

A discussion of the assumptions used in determining grant date fair value may be found in Note 8 to our consolidated financial statements for the year ended December 31, 2023.

Amounts represent annual cash bonuses earned for the applicable fiscal year.

The annual cash bonuses are paid in the first quarter of the calendar year following the year to which the cash bonus relates.

Amounts in this column include for the year ended December 31, 2023 (i) in the case of Mr.

Shukla, $583 consists of the dollar value of life insurance premiums we paid with respect to term life insurance and $9,900 in a matching contribution under our 401(k) plan, (ii) in the case of Dr.

Mahadevia, $340 consists of the dollar value of life insurance premiums we paid with respect to term life insurance, and $9,419 in a matching contribution under our 401(k) plan, $225,719 consists of the pro-rata bonus for calendar year 2023, paid pursuant to the Mahadevia Separation Agreement (as defined below), $11,509 consists of COBRA payments pursuant to the Mahadevia Separation Agreement, $197,250 consists of compensation earned during the year ended December 31, 2023 pursuant to the Mahadevia Consulting Agreement (as defined below), and $31,250 consists of cash compensation earned for his services as a member of our board of directors during the year ended December 31, 2023, and $23,200 consists of RSUs granted for service on our board of directors, each as further described below under “Director Compensation,” (iii) in the case of Ms.

Joseph, $583 consists of the dollar value of life insurance premiums we paid with respect to term life insurance and $6,874 in a matching contribution under our 401(k) plan and (iv) in the case of Mr.

Keutzer, $583 consists of the dollar value of life insurance premiums we paid with respect to term life insurance and $9,900 in a matching contribution under our 401(k) plan.

Mahadevia served as our Chief Executive Officer and President until August 2023.

Thereafter, Dr.

Mahadevia continued to serve as a member of the Board and serves as a consultant to the Company.

Joseph’s employment as our Chief Legal Officer ended effective March 6, 2024.

Narrative Disclosure to Summary Compensation Table

Our employment and consulting arrangements with the named executive officers are described below.

Satyavrat Shukla

On December 9, 2020, we entered into an employment agreement with Mr.

Shukla with respect to his employment as our Chief Financial Officer, as amended on November 10, 2022.

The terms of Mr.

Shukla’s agreement provided for an annual base salary of $425,000 prorated for fiscal year 2021, and eligibility for an annual incentive bonus, with a target bonus opportunity of 40% of his

then-current base salary, subject to adjustment by the Board of Directors or Compensation Committee.

Shukla’s annual base salary has been subsequently increased over time.

As of July 1, 2021, Mr.

Shukla's base salary was increased to $460,000, with a target bonus opportunity of 40% of his base salary.

In December 2021, Mr.

Shukla’s base salary was increased, effective February 1, 2022, to $480,000 with a target bonus opportunity of 40% of his base salary.

In January 2023, Mr.

Shukla’s base salary was increased, effective February 1, 2023, to $489,600 with a target bonus opportunity of 40% of his base salary.

On June 13, 2023, we entered into an Amended and Restated Employment Agreement with Mr.

Shukla with connection with his appointment as our Chief Executive Officer and President (the “Shukla Amended Employment Agreement”).

Under the terms of the Shukla Amended Employment Agreement, (i) the Company shall pay Mr.

Shukla an annual base salary (the “Base Salary”) of $575,000;

Shukla shall be eligible to receive an annual cash bonus (the “Annual Performance Bonus”), with the target amount of such Annual Performance Bonus equal to 50% of Mr.

Shukla’s Base Salary in the year to which the Annual Performance Bonus relates;

provided that the actual amount of the Annual Performance Bonus may be greater or less than such target amount;

provided further that Mr.

Shukla’s Annual Performance Bonus for the 2023 performance year shall be pro-rated such that it shall be based on a Base Salary of $489,600 for the period from January 1, 2023 to July 31, 2023 and on a Base Salary of $575,000 for the period from the Transition Date to December 31, 2023;

and (iii) the Company awarded Mr.

Shukla 266,000 restricted stock units (the “Shukla RSUs”) under the Plan on the Transition Date;

the Shukla RSUs are subject to the terms and conditions of the Plan and the restricted stock unit agreement between Mr.

Shukla and Company entered into pursuant thereto (the “Shukla RSU Agreement”);

and the Shukla RSUs shall vest in four equal annual installments beginning on the first anniversary of the Transition Date, except as otherwise provided in the Shukla RSU Agreement.

In January 2024, Mr.

Shukla’s base salary was increased, effective January 1, 2024, to $603,750 with a target bonus opportunity remaining at 50% of his base salary.

The Shukla Amended Employment Agreement also provides for the following severance payments upon termination by the Company without Cause (as defined in the Shukla Amended Employment Agreement) or by Mr.

Shukla for Good Reason (as defined in the Shukla Amended Employment Agreement):

(i) payment of his then-current Base Salary for a period of 12 months following termination;

(ii) a pro-rated target bonus for the period during which Mr.

Shukla was employed in the year of termination;

and (iii) continued coverage under the Company’s group health insurance plan until the earlier of 12 months from termination or the date Mr.

Shukla becomes eligible for medical benefits with another employer.

Further, the Shukla Amended Employment Agreement provides that upon termination by the Company without Cause or by Mr.

Shukla for Good Reason within (i) 90 days prior to the earlier to occur of a Change of Control (as defined in the Shukla Amended Employment Agreement) or the execution of a definitive agreement, the consummation of which would result in a Change of Control or (ii) one year following a Change of Control, Mr.

Shukla will be entitled to receive:

(i) a lump sum payment equal to 18 months of his then-current Base Salary plus an amount equal to one-and-one-half times the target amount of his Annual Performance Bonus;

(ii) acceleration of all unvested equity awards as of the date of termination;

and (iii) continued coverage under the Company’s group health insurance plan until the earlier of 18 months from termination or the date Mr.

Shukla becomes eligible for medical benefits with another employer.

Payment in each case is subject to Mr.

Shukla’s execution of a release satisfactory to the Company following such termination.

In addition, if Mr.

Shukla’s employment terminates as a result of disability or death, he will be entitled to receive a pro-rated target bonus for the period during which he was employed in the year of termination.

Ankit Mahadevia, M.D.

On October 20, 2017, we entered into an employment agreement with Dr.

Mahadevia with respect to his employment as our Chief Executive Officer, as amended on November 10, 2022.

The terms of Dr.

Mahadevia’s agreement provided for an annual base salary of $400,000, and eligibility for an annual incentive bonus, with a target bonus opportunity of 30% of his then-current base salary, subject to adjustment by the Board of Directors or Compensation Committee.

Mahadevia’s annual base salary and target bonus opportunity were subsequently increased over time.

In December 2021, Dr.

Mahadevia’s base salary was increased, effective February 1, 2022, to $635,000, with a target bonus opportunity of 60% of his base salary.

In January 2023, Dr.

Mahadevia’s base salary was increased, effective February 1, 2023, to $647,700, with a target bonus opportunity of 60% of his base salary.

Mahadevia stepped down as Chief Executive Officer effective August 1, 2023.

On June 13, 2023, we entered into a (i) Transition and Separation Agreement with Dr.

Mahadevia (the “Mahadevia Separation Agreement”) and (ii) Consulting Agreement with Dr.

Mahadevia (the “Mahadevia Consulting Agreement”), each as described below.

Mahadevia’s employment agreement provided for the following increased severance payments upon termination by us without Cause (as defined below) or by Dr.

Mahadevia for Good Reason (as defined below):

(i) payment of his then current base salary for a period of 12 months following termination;

(ii) a pro-rated target bonus for the period during which Dr.

Mahadevia was employed in the year of termination;

and (iii) continued coverage under our group health insurance plan until the earlier of 12 months from termination or the date Dr.

Mahadevia becomes eligible for medical benefits with another employer.

Further, the agreement provided that upon termination by us without Cause or by Dr.

Mahadevia for Good Reason within 90 days prior to the earlier to occur of a Change of Control (as defined below) or the execution of a definitive agreement the consummation of which would result in a Change of Control or one year following a Change of Control (a “Change of Control Termination”), Dr.

Mahadevia was entitled to

receive (i) a lump sum payment equal to 18 months of his then-current base salary plus the amount of his then-current target performance bonus;

(ii) acceleration of all unvested equity awards as of the date of termination;

and (iii) continued coverage under our group health insurance plan until the earlier of 12 months from termination or the date Dr.

Mahadevia becomes eligible for medical benefits with another employer.

Payment in each case was subject to Dr.

Mahadevia’s execution of a release satisfactory to us following such termination.

In addition, if Dr.

Mahadevia’s employment terminated as a result of disability or death, he was entitled to receive a pro-rated target bonus for the period during which Dr.

Mahadevia was employed in the year of termination.

The agreement also provided that Dr.

Mahadevia shall serve as a member of our Board of Directors during his employment with us until the term of his directorship expires and he is not re-elected or his earlier resignation or removal from our Board of Directors.

On June 13, 2023, we entered into the Mahadevia Separation Agreement.

Pursuant to the terms of the Mahadevia Separation Agreement, (i) Dr.

Mahadevia remained eligible to receive a bonus amount representing a pro-rata bonus for calendar year 2023, subject to the discretion of the Board, calculated through August 1, 2023 (the “Transition Date”), which was paid within ten days following the Transition Date;

Mahadevia is eligible for and elects to continue his health insurance coverage under the Consolidated Omnibus Budget Reconciliation Act (“COBRA”) following the Transition Date, then the Company shall pay his monthly premium under COBRA until the earliest of (A) January 31, 2024;

(B) the expiration of his continuation coverage under COBRA;

or (C) the date when he becomes eligible to receive health insurance coverage in connection with new employment or self-employment;

(iii) that the Company enter into the Mahadevia Consulting Agreement;

(iv) notwithstanding any terms of the Company’s 2017 Plan, or any award agreements to the contrary, in the event of a Change of Control (as defined in the Mahadevia Consulting Agreement) and provided Dr.

Mahadevia is a member of the Board on the effective date of the Change of Control, Dr.

Mahadevia shall become fully vested in any and all equity awards outstanding as of the effective date of the Change of Control;

Mahadevia was appointed by the Board of Directors to serve as Chairman of the Board, effective as of the Transition Date.

On June 13, 2023, we entered into the Mahadevia Consulting Agreement.

Pursuant to the terms of the Mahadevia Consulting Agreement, Dr.

Mahadevia will perform certain consulting services for the Company which commenced on the Transition Date and continues through July 31, 2025, including advising the Company on general operational and strategic matters (the “Mahadevia Services”).

Under the Mahadevia Consulting Agreement, the Company shall pay Dr.

Mahadevia (i) $54,000 per month for the Mahadevia Services from the Transition Date through January 31, 2024 and (ii) an hourly rate of $310.00 per hour beginning on February 1, 2024 and continuing through July 31, 2025.

Further, the equity that Dr.

Mahadevia received under the 2017 Plan and any Stock Option Agreement or Restricted Stock Unit Agreement executed pursuant thereto prior to the Transition Date (collectively, the “Mahadevia Award Agreements”) shall continue to vest in accordance with the terms of the Plan and the Mahadevia Award Agreements during the term of the Mahadevia Consulting Agreement.

Mahadevia may exercise any vested options during the term of the Mahadevia Consulting Agreement and for 90 days following a termination event triggering an exercise period applicable to same (but no later than the date such award expires) in accordance with the terms of the Plan and the applicable Mahadevia Award Agreements.

In addition, in the event of a Change of Control (as defined in Mahadevia Consulting Agreement) on or before July 31, 2025, Dr.

Mahadevia shall become fully vested in any and all equity awards outstanding as of the effective date of such Change of Control, provided that the Mahadevia Consulting Agreement remains in effect as of the effective date of such Change of Control.

Tamara Joseph

On November 6, 2020, we entered into an employment agreement with Ms.

Joseph with respect to her employment as our Chief Legal Officer, as amended on November 10, 2022.

The terms of Ms.

Joseph’s agreement provided for an annual base salary of $385,000 prorated for fiscal year 2020, and eligibility for an annual incentive bonus, with a target bonus opportunity of 40% of her then-current base salary, subject to adjustment by the Board of Directors or Compensation Committee.

Joseph’s annual base salary has been subsequently increased over time.

As of July 1, 2021, Ms.

Joseph's base salary was increased to $435,000, with a target bonus opportunity of 40% of her base salary.

In December 2021, Ms.

Joseph’s base salary was increased, effective February 1, 2022, to $450,000 with a target bonus opportunity of 40% of her base salary.

In January 2023, Ms.

Joseph’s base salary was increased, effective February 1, 2023, to $459,000 with a target bonus opportunity of 40% of her base salary.

In January 2024, Ms.

Joseph’s base salary was increased, effective January 1, 2024, to $475,065 with a target bonus opportunity of 40% of her base salary.

The agreement also provides for the following severance payments upon termination by us without Cause or by Ms.

Joseph for Good Reason:

(i) payment of her then-current base salary for a period of nine months following termination;

(ii) a pro-rated target bonus for the period during which Ms.

Joseph was employed in the year of termination;

and (iii) continued coverage under our group health insurance plan until the earlier of 12 months from termination or the date Ms.

Joseph becomes eligible for medical benefits with another employer.

Further, the agreement provides that upon termination by us without Cause or by Ms.

Joseph for Good Reason within 90 days prior to the earlier to occur of a Change of Control or a Change of Control Termination, Ms.

Joseph will be entitled to receive:

(i) a lump sum payment equal to 12 months of her then-current base salary plus the amount of her then-current target performance bonus;

(ii) acceleration of all unvested equity awards as of the date of termination;

and (iii) continued coverage under our group health insurance plan until the earlier of 12 months from termination or the date Ms.

Joseph becomes eligible for medical benefits with another employer.

Payment in each case is subject to Ms.

Joseph’s execution of a release satisfactory to us following

such termination.

In addition, if Ms.

Joseph’s employment terminates as a result of disability or death, she shall be entitled to receive a pro-rated target bonus for the period during which Ms.

Joseph was employed in the year of termination.

Effective as of March 6, 2024, Ms.

Joseph’s employment as our Chief Legal Officer ended.

In connection with Ms.

Joseph stepping down, she is entitled to receive severance pay in the amount of $356,298.75, payable as continued salary in accordance with the our regular payroll dates and a pro rated cash bonus equal to $34,266.98 for the year ending December 31, 2024, which will be paid to Ms.

Joseph when we pay the 2024 annual bonuses to our employees in 2025, but in any event no later than March 15, 2025.

To implement the foregoing, we and Ms.

Joseph entered into a Separation Agreement.

We also entered into the Joseph Consulting Agreement, effective as of March 6, 2024, pursuant to which Ms.

Joseph will provide consulting services to us on an hourly, as needed basis, for a term of nine months following March 6, 2024 at a rate of $395.00 per hour.

Joseph’s employee stock options and RSUs will continue to vest during the term of the Joseph Consulting Agreement and after the term of the Joseph Consulting Agreement ends, all of Ms.

Joseph’s then vested and unexercised options and RSUs will be exercisable for 90 days in accordance with the terms of such options and RSUs and the 2017 Plan and the 2019 Inducement Plan, as applicable.

Timothy Keutzer

On January 1, 2020, we entered into an employment agreement with Mr.

Keutzer with respect to his employment as our Chief Development Officer, as amended on November 10, 2022.

The terms of Mr.

Keutzer’s agreement provided for an annual base salary of $ 330,000 and eligibility for an annual incentive bonus, with a target bonus opportunity of 40% of his then-current base salary, subject to adjustment by the Board of Directors or Compensation Committee.

Keutzer’s annual base salary has been subsequently increased over time.

In December 2021, Mr.

Keutzer’s base salary was increased, effective February 1, 2022, to $425,000 with a target bonus opportunity of 40% of his base salary.

On February 1, 2023, we entered into an Amended and Restated Employment Agreement with Mr.

Keutzer with connection with his appointment as our Chief Operating Officer (the “Keutzer Amended Employment Agreement”).

Under the terms of the Keutzer Amended Employment Agreement, the Company shall pay Mr.

Keutzer an annual base salary of $459,000, with a target bonus opportunity of 40% of his base salary.

In January 2024, Mr.

Keutzer’s base salary was increased, effective January 1, 2024, to $475,065 with a target bonus opportunity remaining at 40% of his base salary.

The agreement also provides for the following severance payments upon termination by us without Cause or by Mr.

Keutzer for Good Reason:

(i) payment of his then-current base salary for a period of nine months following termination;

(ii) a pro-rated target bonus for the period during which Mr.

Keutzer was employed in the year of termination;

and (iii) continued coverage under our group health insurance plan until the earlier of 12 months from termination or the date Mr.

Keutzer becomes eligible for medical benefits with another employer.

Further, the agreement provides that upon termination by us without Cause or by Mr.

Keutzer for Good Reason within 90 days prior to the earlier to occur of a Change of Control or a Change of Control Termination, Mr.

Keutzer will be entitled to receive:

(i) a lump sum payment equal to 12 months of his then-current base salary plus the amount of his then-current target performance bonus;

(ii) acceleration of all unvested equity awards as of the date of termination;

and (iii) continued coverage under our group health insurance plan until the earlier of 12 months from termination or the date Mr.

Keutzer becomes eligible for medical benefits with another employer.

Payment in each case is subject to Mr.

Keutzer ‘s execution of a release satisfactory to us following such termination.

In addition, if Mr.

Keutzer’s employment terminates as a result of disability or death, he shall be entitled to receive a pro-rated target bonus for the period during which Mr.

Keutzer was employed in the year of termination.

Under each of the employment agreements, Cause means (i) the executive’s conviction of (A) a felony or (B) any misdemeanor involving moral turpitude, deceit, dishonesty or fraud;

(ii) the executive’s willful failure or refusal to comply with lawful directions of our Board of Directors (or, for Mr.

Keutzer and Ms.

Joseph, the lawful directions of the Chief Executive Officer), which failure or refusal continues for more than thirty days after written notice is given to the executive by our Board of Directors (or, for Mr.

Keutzer and Ms.

Joseph, by the Chief Executive Officer), which notice sets forth in reasonable detail the nature of such failure or refusal;

(iii) willful and material breach by the executive of a written company policy applicable to the executive or the executive’s covenants and/or obligations under his or her employment agreement or the material breach of the executive’s proprietary information and inventions assignment agreement;

and/or (iv) material misconduct by the executive that seriously discredits or damages us or any of our affiliates.

Under each of the employment agreements, Good Reason means (i) relocation of the executive’s principal business location to a location more than thirty (30) miles from the executive’s then-current business location;

(ii) a material diminution in the executive’s duties, authority or responsibilities;

(iii) a material reduction in the executive’s base salary;

(iv) willful and material breach by us of our covenants and/or obligations under the executive’s employment agreement;

or (v) within one year following a Change of Control, the executive is not an executive of the parent company, provided that the executive’s roles responsibilities and scope of authority within the subsidiary is not comparable to the executive’s roles, responsibilities and scope of authority with us prior to the Change of Control.

Under each of the employment agreements, Change of Control means (i) any person (as such term is used in Sections 13(d) and 14(d) of the Exchange Act) becomes the beneficial owner, directly or indirectly, of securities of the Company representing fifty percent (50%) or more of the total voting power represented by the Company’s then outstanding voting securities (excluding for this purpose any such voting securities held by the Company, or any affiliate, parent or subsidiary of the Company, or by any employee benefit plan of the Company) pursuant to a transaction or a series of related transactions;

(ii) a merger or consolidation of the Company other than a merger or consolidation which would result in the voting securities of the Company outstanding immediately prior thereto continuing to represent (either by remaining outstanding or by being converted into voting securities of the surviving entity or the parent of such corporation) at least fifty percent (50%) of the total voting power represented by the voting securities of the Company or such surviving entity or parent of such corporation, as the case may be, outstanding immediately after such merger or consolidation;

(iii) our stockholders approve an agreement for the sale or disposition by the Company of all or substantially all of our assets;

or (iv) a change in the composition of our Board of Directors, as a result of which fewer than a majority of the directors are incumbent directors.

All of our executive officers have entered into our standard proprietary information and inventions assignment agreement.

Outstanding Equity Awards at 2023 Fiscal Year-End

The following table shows grants of stock options and awards outstanding on the last day of the fiscal year ended December 31, 2023 to each of the named executive officers.

Option Awards

Unexercisable

Satyavrat Shukla

Ankit Mahadevia, M.D.

Tamara Joseph

Timothy Keutzer

The market value of the stock awards is based on the closing price of our common stock of $1.47 per share on December 29, 2023.

25% of the options vested on January 4, 2022 and an additional 1/36th of the remaining shares vest monthly until the option is fully vested.

In addition, in the event of a Change of Control Termination, the vesting of these options will accelerate in accordance with the terms of the option and his or her employment agreement.

25% of the options vested on February 1, 2023 and an additional 1/36th of the remaining shares vest monthly until the option is fully vested.

In addition, in the event of a Change of Control Termination, the vesting of these options will accelerate in accordance with the terms of the option and his or her employment agreement.

Consists of RSUs.

Each RSU represents the right to receive one share of common stock upon vesting.

The RSUs vest in four equal annual installments beginning on August 26, 2022, subject to the individual's continued service through the applicable vesting date.

Consists of RSUs.

Each RSU represents the right to receive one share of common stock upon vesting.

The RSUs vest in four equal annual installments beginning on February 1, 2023, subject to the individual's continued service through the applicable vesting date.

Consists of RSUs.

Each RSU represents the right to receive one share of common stock upon vesting.

The RSUs vest in four equal annual installments beginning on February 1, 2024, subject to the individual's continued service through the applicable vesting date.

Consists of RSUs.

Each RSU represents the right to receive one share of common stock upon vesting.

The RSUs vest in four equal annual installments beginning on August 1, 2024 subject to the individual's continued service through the applicable vesting date.

100% of these options vested on August 24, 2019.

100% of these options vested on April 28, 2020.

100% of these options vested on July 6, 2017.

100% of these options vested on July 6, 2021.

100% of these options vested on December 13, 2021.

100% of these options vested on January 2, 2023.

25% of the options vested on February 3, 2021 and an additional 1/36th of the remaining shares vest monthly until the option is fully vested.

In addition, in the event of a Change of Control Termination, the vesting of these options will accelerate in accordance with the terms of the option and his or her employment agreement.

25% of the options vested on February 1, 2022 and an additional 1/36th of the remaining shares vest monthly until the option is fully vested.

In addition, in the event of a Change of Control Termination, the vesting of these options will accelerate in accordance with the terms of the option and his or her employment agreement.

25% of the options vested on December 2, 2021 and an additional 1/36th of the remaining shares vest monthly until the option is fully vested.

In addition, in the event of a Change of Control Termination, the vesting of these options will accelerate in accordance with the terms of the option and his or her employment agreement.

During the year ended December 31, 2023, the named executive officers did not exercise any stock options.

2022 Retention Cash Bonus and Performance Awards

On July 1, 2022, upon recommendation of the Compensation Committee, the Board of Directors approved a cash and RSU retention award for the Company’s executive officers, including awards to Mr.

Mahadevia, Ms.

Joseph and Mr.

Keutzer consisting of the following:

Shukla received:

(i) a cash bonus of $168,000, which was paid on November 30, 2022, and (ii) upon the achievement of certain performance criteria as of May 31, 2023, a cash payment of $336,000, which was paid in June 2023.

Mahadevia received:

(i) a cash bonus of $254,000, which was paid on November 30, 2022, and (ii) upon the achievement of certain performance criteria as of May 31, 2023, a cash payment of $508,000, which was paid in June 2023.

Joseph received:

(i) a cash bonus of $157,500, which was paid on November 30, 2022, and (ii) upon the achievement of certain performance criteria as of May 31, 2023, a cash payment of $315,000, which was paid in June 2023.

Keutzer received:

(i) a cash bonus of $148,785, which was paid on November 30, 2022, and (ii) upon the achievement of certain performance criteria as of May 31, 2023, a cash payment of $297,500, which was paid in June 2023.

The payments were based on the achievement of certain performance criteria by May 31, 2023 relating to pipeline execution, business development, and financial stewardship.

Potential Payments upon Termination or Change-In-Control

The employment agreements provide for the following severance payments upon termination by us without Cause or by the employee for Good Reason:

(i) payment of the employee’s then-current base salary for a period of nine months following termination (12 months in the case of the Chief Executive Officer);

(ii) a pro-rated target bonus for the period during which the employee was employed in the year of termination;

and (iii) continued coverage under our group health insurance plan until the earlier of 12 months from termination or the date the employee becomes eligible for medical benefits with another employer.

Further, the agreements provide that upon termination by us without Cause or by the employee for Good Reason within 90 days prior to or one year following the earlier to occur of a Change of Control (as defined in the executive’s employment agreements) or the execution of a definitive agreement the consummation of which would result in a Change of Control, the employee will be entitled to receive:

(i) a lump sum payment equal to 12 months of the employee’s then-current base salary plus a pro-rated target bonus for the period during which the employee was employed in the year of termination;

(ii) acceleration of unvested equity awards as of the date of termination in accordance with the terms of the executive’s employment agreement, as described above under “Narrative Disclosure to Summary Compensation Table;” and (iii) continued coverage under our group health insurance plan until the earlier of 12 months from termination or the date the employee becomes eligible for medical benefits with another employer.

Payment in each case is subject to the employee’s execution of a release satisfactory to us following such termination.

In addition, if the employee’s employment terminates as a result of disability or death, he or she shall be entitled to receive a pro-rated target bonus for the period during which the employee was employed in the year of termination.

Director Compensation

The following table shows the total compensation paid or accrued during the fiscal year ended December 31, 2023 to each of our current non-employee directors.

Directors who are employed by us are not compensated for their service on our Board of Directors.

Fees Earned or

Paid in Cash ($)

Awards ($) (1)

Awards* ($) (2)(6)

Milind Deshpande, Ph.D.

Scott Jackson

Ankit Mahadevia, M.D.

Pottage, Jr., M.D.

Cynthia Smith

Kathleen Tregoning

Patrick Vink, M.D.

These amounts represent the aggregate grant date fair value for RSU awards computed in accordance with ASC 718.

A discussion of the assumptions used in determining grant date fair value may be found in Note 8 to our consolidated financial statements, included in this Annual Report on Form 10-K for the fiscal year ended December 31, 2023.

These amounts represent the aggregate grant date fair value of options granted to each director in the fiscal year ended December 31, 2023, computed in accordance with FASB ASC Topic 718.

Mahadevia served as our President and Chief Executive Officer for part of 2023;

as such, his compensation earned as a director is disclosed in the Summary Compensation Table above.

Represents an option to purchase 30,942 shares of common stock at an exercise price of $1.74.

The shares underlying the option award vested and became fully exercisable on December 31, 2023.

Represents an option to purchase 15,471 shares of common stock at an exercise price of $1.74.

The shares underlying the option award vested and became fully exercisable on December 31, 2023.

As of December 31, 2023, the aggregate number of options held by each of our current non-employee directors was as follows (representing both exercisable and unexercisable option awards, none of which have been exercised):

Number of Shares

Stock Options

Milind Deshpande, Ph.D.

Scott Jackson

Ankit Mahadevia, M.D.

Pottage, Jr., M.D.

Cynthia Smith

Kathleen Tregoning

Patrick Vink, M.D.

Non-Employee Director Compensation Policy

Under our Non-Employee Director Compensation Policy, as amended (the “Non-Employee Director Compensation Policy”), each non-employee director is eligible to receive compensation for his or her service consisting of annual cash retainers and equity awards.

Our non-employee directors received the following annual retainers for their service as of December 31, 2023:

Board Chairperson (additional retainer)

Lead Director, if any (additional retainer)

Audit Committee Chair

Compensation Committee Chair

Nominating and Governance Committee Chair

Development Committee Chair

Audit Committee Member

Compensation Committee Member

Nominating and Governance Committee Member

Development Committee Member

Our Non-Employee Director Compensation Policy provides the following with respect to equity awards to non-employee directors:

(i) the initial equity award consisting of a non-qualified stock option to purchase shares of our common stock upon first appointment to our Board of Directors and vesting in equal monthly installments until the third anniversary of the grant date subject to the non-employee director’s continued service in the amount of 15,000 shares, and (ii) annual equity awards consisting of a grant of 20,000 RSUs (each RSU relating to one share of our common stock) on the date of our annual meeting of stockholders.

The RSUs vest on the first anniversary of the grant date, subject to the director’s continued service, and are issued under, and are subject to the terms of, the 2017 Plan.

The policy also provides that, prior to the beginning of each calendar year, a non-employee director may elect to receive all or a portion of his or her base annual fee for service on our Board of Directors in the form of a non-qualified stock option to purchase a number of shares of our common stock based on the Black-Scholes value of such option, which option will be granted on the first business day of the calendar year.

These options vest in four quarterly installments on the last day of each calendar quarter during the calendar year, subject to the continued service of the non-employee director.

Directors may be reimbursed for travel, food, lodging and other expenses directly related to their service as directors.

Directors are also entitled to the protection provided by their indemnification agreements and the indemnification provisions in our Amended and Restated Certificate of Incorporation, as amended, and Amended and Restated Bylaws.

The response to this item is incorporated by reference from the discussion responsive thereto under the captions “Executive Officer and Director Compensation” and “Management and Corporate Governance Matters - Compensation Committee Interlocks and Insider Participation” in our proxy statement for the 2025 Annual Meeting of Stockholders to be filed with the SEC within 120 days after the end of the fiscal year covered by this Annual Report on Form 10-K.

Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters.

The following table sets forth certain information with respect to the beneficial ownership of our common stock as of March 8, 2024 for (a) the executive officers named in the Summary Compensation Table on Item 11 of this Amendment, (b) each of our directors and director nominees, (c) all of our current directors and executive officers as a group and (d) each stockholder known by us to own beneficially more than 5% of our common stock.

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

We deem shares of common stock that may be acquired by an individual or group within 60 days of March 8, 2024 pursuant to the exercise of options to be outstanding for the purpose of computing the percentage ownership of such individual or group, but not outstanding for the purpose of computing the percentage ownership of any other person shown in the table.

Except as indicated in footnotes to this table, we believe that the stockholders named in this table have sole voting and investment power with respect to all shares of common stock shown to be beneficially owned by them based on information provided to us by these stockholders.

Percentage of ownership is based on 53,869,139 shares of common stock outstanding on March 8, 2024.

Name of Beneficial Owner

Number of Shares

Percent of Shares

Beneficially Owned

Principal Stockholders

GSK Equity Investments, Limited (1)

Anson Funds Management, LP (2)

Named Executive Officers and Directors

Satyavrat Shukla (3)

Timothy Keutzer (4)

Tamara Joseph (5)

Milind Deshpande, Ph.D.

Scott Jackson (7)

Ankit Mahadevia, M.D.

Pottage, Jr., M.D.

Cynthia Smith (10)

Kathleen Tregoning (12)

Patrick Vink, M.D.

All current executive officers and directors as a group (11 persons) (14)

* Indicates beneficial ownership of less than 1%.

Consists of shares of common stock owned by GSK Equity Investments, Limited (formerly S.R.

One, Limited), and Glaxo Group Limited, each of which is an indirect wholly owned subsidiary of GSK plc.

The address for GSK plc is 980 Great West Road, Brentford, Middlesex TW8 9GS, England.

This information is based solely on a Schedule 13D/A filed by GlaxoSmithKline plc with the SEC on January 20, 2023, which reported ownership as of November 14, 2022.

Consists of shares of common stock owned by Anson Funds Management LP.

The address for Anson Funds Management LP is 16000 Dallas Parkway, Suite 800, Dallas, Texas 75248.

This information is based solely on a Schedule 13G filed by Anson Funds Management LP with the SEC on February 14, 2024, which reported ownership as of December 31, 2023.

Consists of 92,419 shares of common stock underlying options that are exercisable as of March 8, 2024 or will become exercisable within 60 days after such date held by Mr.

Consists of (i) 63,813 shares of common stock and (ii) 237,542 shares of common stock underlying options that are exercisable as of March 8, 2024 or will become exercisable within 60 days after such date held by Mr.

Consists of (i) 61,378 shares of common stock and (ii) 93,982 shares of common stock underlying options that are exercisable as of March 8, 2024 or will become exercisable within 60 days after such date held by Ms.

Joseph, our former Chief Legal Officer.

Consists of (i) 16,454 shares of common stock and (ii) 83,664 shares of common stock underlying options that are exercisable as of March 8, 2024 or will become exercisable within 60 days after such date held by Dr.

Consists of 30,000 shares of common stock underlying options that are exercisable as of March 8 , 2024 or will become exercisable within 60 days after such date held by Mr.

Consists of (i) 65,817 shares of common stock held by Mahadevia-Mehta Family Trust, of which Dr.

Mahadevia is the trustee, and (ii) 154,052 shares of common stock and (iii) 1,223,183 shares of common stock underlying options that are exercisable as of March 8, 2024 or will become exercisable within 60 days after such date held by Dr.

Consists of 33,219 shares of common stock underlying options that are exercisable as of March 8, 2024 or will become exercisable within 60 days after such date held by Dr.

Consists of 35,848 shares of common stock underlying options that are exercisable as of March 8, 2024 or will become exercisable within 60 days after such date held by Ms.

Consists of 63,893 shares of common stock underlying options that are exercisable as of March 8, 2024 or will become exercisable within 60 days after such date held by Mr.

Consists of 56,354 shares of common stock underlying options that are exercisable as of March 8, 2024 or will become exercisable within 60 days after such date held by Ms.

Consists of 82,067 shares of common stock underlying options that are exercisable as of March 8, 2024 or will become exercisable within 60 days after such date held by Dr.

See 3 and 4 and 6 through 13 above;

also includes shares of common stock underlying options that are exercisable as of March 8, 2024 or will become exercisable within 60 days after such date held by Dr.

Hamed, who is an executive officer but not a named executive officer.

Equity Compensation Plan Information

The following table provides certain aggregate information with respect to all of our equity compensation plans in effect as of December 31, 2023:

Plan category

Number of securities to be

issued upon exercise of

outstanding options,

warrants and rights (#) (3)

Weighted-average exercise

price of outstanding

options, warrants and

rights ($) (4)

Number of securities

remaining for future issuance

under equity compensation

plans (excluding securities

reflected in column (a) (#)

Equity compensation plans approved

by stockholders (1)

Equity compensation plans not

approved by stockholders (2)

This plan category consists of our 2017 Plan.

This plan category consists of our 2019 Inducement Plan.

Represents shares of common stock issuable upon the exercise of outstanding stock options and vesting of outstanding RSUs.

Represents the weighted-average exercise price of outstanding options to purchase shares of common stock issued under our plans.

Benefits Programs

Each named executive employee is eligible to participate in our benefits programs, which include health, life, disability and dental insurance and a 401(k) retirement savings plan.

Spero Therapeutics, Inc.’s 2017 Stock Incentive Plan

We adopted the Spero Therapeutics, Inc.

2017 Plan on June 28, 2017, as amended on October 18, 2017 and August 17, 2021, September 15, 2022 and October 5, 2023.

The 2017 Plan will expire on June 30, 2027.

Under the 2017 Plan, we may grant incentive stock options, non-qualified stock options, restricted and unrestricted stock awards and other stock-based awards.

Since its adoption, there have been 12,188,627 shares of our common stock authorized for issuance under the 2017 Plan.

As of March 8, 2024, a total of 1,930,722 shares are available for future grant under the 2017 Plan.

Our Board of Directors is authorized to administer the 2017 Plan.

In accordance with the provisions of the 2017 Plan, our Board of Directors determines the terms of the options and other awards issued pursuant thereto, including the following:

• which employees, directors and consultants shall be granted awards;

• the number of shares of common stock subject to options and other awards;

• the exercise price of each option, which generally shall not be less than fair market value of the common stock on the date of grant;

• the termination or cancellation provisions applicable to the options;

• the terms and conditions of other awards, including conditions for repurchase, termination or cancellation, issue price and repurchase price;

• all other terms and conditions upon which each award may be granted in accordance with the 2017 Plan.

No participant may receive awards for more than 1,000,000 shares of our common stock in any fiscal year.

In addition, our Board of Directors or any committee to which our Board of Directors delegates authority may, with the consent of the affected plan participants, amend outstanding awards consistent with the terms of the 2017 Plan.

Upon a merger, consolidation, or sale of all or substantially all of our assets, our Board of Directors or any committee to which our Board of Directors delegates authority, or the Board of Directors of any corporation assuming the our obligations, may, in its sole discretion, take any one or more of the following actions pursuant to the 2017 Plan, as to some or all outstanding awards, to the extent not otherwise agreed under any individual agreement:

• provide that outstanding options will be assumed or substituted for options of the successor corporation;

• provide that the outstanding options must be exercised within a certain number of days, either to the extent the options are then exercisable, or at our Board of Directors’ discretion, any such options being made partially or fully exercisable;

• terminate outstanding options in exchange for a cash payment of an amount equal to the difference between (a) the consideration payable upon consummation of the corporate transaction to a holder of the number of shares into which such option would have been exercisable to the extent then exercisable, or in our Board of Directors’ discretion, any such options being made partially or fully exercisable, and (b) the aggregate exercise price of those options;

• provide that outstanding stock grants will be substituted for shares of the successor corporation or consideration payable with respect to our outstanding stock in connection with the corporate transaction;

• terminate outstanding stock grants in exchange for payment of an amount equal to the consideration payable upon consummation of the corporate transaction to a holder of the same number of shares comprising the stock grant, to the extent the stock grant is no longer subject to any forfeiture or repurchase rights, or at our Board of Directors’ discretion, all forfeiture and repurchase rights being waived upon the corporate transaction.

For purposes of determining such payments, in the case of a corporate transaction the consideration for which, in whole or in part, is other than cash, the consideration other than cash shall be valued at the fair market value thereof as determined in good faith by our Board of Directors.

Spero Therapeutics, Inc.’s 2019 Inducement Equity Incentive Plan

On March 11, 2019, the Board of Directors adopted Spero Therapeutics, Inc.’s 2019 Inducement Plan, as amended on June 23, 2020, December 22, 2022, July 27, 2023, and October 30, 2023.

The Board of Directors initially reserved 331,500 shares of our common stock under the 2019 Inducement Plan to be used exclusively for grants of awards to individuals that were not previously our employees or directors, as an inducement to the individual’s entry into employment with us within the meaning of Rule 5635(c)(4) of the Nasdaq Listing Rules.

As previously disclosed, in June 2020, the Board of Directors approved an amendment to the 2019 Inducement Plan to increase the number of shares of common stock authorized for issuance thereunder by 700,000 shares.

In December 2022, the Board of Directors approved an amendment to the 2019 Inducement Plan to increase the number of shares of common stock authorized for issuance thereunder by 875,000 shares.

In July 2023, the Board of Directors approved an amendment to the 2019 Inducement Plan to increase the number of shares of common stock authorized for issuance thereunder by 250,000 shares.

In October 2023, the Board of Directors approved an amendment to the 2019 Inducement Plan to increase the number of shares of common stock authorized for issuance thereunder by 500,000 shares.

The 2019 Inducement Plan was adopted without stockholder approval pursuant to Rule 5635(c)(4).

The 2019 Inducement Plan provides for the grant of equity-based awards, including options, restricted and unrestricted stock awards, and other stock-based awards, and its terms are substantially similar to the 2017 Plan, but with such other terms and conditions intended to comply with the Nasdaq inducement award exception.

As of March 8, 2024, there were 2,102,141 shares outstanding and 2,421,112 shares available for grant under the 2019 Inducement Plan.

Rule 10b5-1 Sales Plans

Our directors and executive officers may adopt written plans, known as Rule 10b5-1 plans, in which they will contract with a broker to buy or sell shares of our common stock on a periodic basis.

Under a Rule 10b5-1 plan, a broker executes trades pursuant to parameters established by the director or officer when entering into the plan, without further direction from the director or officer.

The director or officer may amend or terminate the plan in limited circumstances.

Our directors and executive officers may also buy or sell additional shares of our common stock outside of a Rule 10b5-1 plan when they are not in possession of material, nonpublic information.

The response to this item is incorporated by reference from the discussion responsive thereto under the captions “Security Ownership of Certain Beneficial Owners and Management” and “Equity Compensation Plans and Other Benefits Plans” in our proxy statement for the 2025 Annual Meeting of Stockholders to be filed with the SEC within 120 days after the end of the fiscal year covered by this Annual Report on Form 10-K.

Certain Relationships and Related Transactions, and Director Independence.

Related Party Transactions

The following is a description of transactions since January 1, 2022, to which we have been a party, in which the amount involved exceeds $120,000, and in which any of our directors, executive officers or holders of more than 5% of our capital stock, or an affiliate or immediate family member thereof, had or will have a direct or indirect material interest.

We refer to such transactions as “related party transactions” and such persons as “related parties.” With the approval of our Board of Directors, we have engaged in the related party transactions described below.

We believe the terms obtained or consideration that we paid or received, as applicable, in connection with the transactions described below were comparable to terms available or the amounts that would be paid or received, as applicable, from unaffiliated third parties.

Transactions with GSK

License Agreement

On September 21, 2022, we entered into the GSK License Agreement with GSK.

Pursuant to the terms of the GSK License Agreement, we granted GSK an exclusive royalty-bearing license, with the right to grant sublicenses, under our intellectual property and regulatory documents and a sublicense under certain intellectual property of Meiji and Meiji’s regulatory documents to develop, manufacture and commercialize the GSK Licensed Products in the GSK Territory.

Under the terms of the GSK License Agreement, we received an upfront payment of $66.0 million for GSK to secure rights to the medicine and are eligible to receive up to $525.0 million in development, sales, and commercial milestones payments, as well as low single-digit to low double-digit tiered royalties on net product sales.

Royalties are subject to reduction in the event of third-party licenses, entry of a generic product or expiration of patent and regulatory exclusivity prior to the tenth anniversary of the first commercial sale of a GSK Licensed Product in a particular country.

In July 2023, we entered into Amendment 1 to the GSK License Agreement, which updated the technology transfer terms of the GSK License Agreement.

In December 2023, we entered into Amendment 2 to the GSK License Agreement, which added a country to the locations for PIVOT-PO.

Under the terms of Amendment 2, we may receive up to an additional $4.3 million in tranched milestones based on activities in such country.

The terms of the License Agreement are described further above under “Business - Collaboration, License and Service Agreements - Tebipenem HBr Agreements - GSK License Agreement.”

Share Purchase Agreement

Concurrently with the execution of the GSK License Agreement, on the GSK Effective Date, we entered into the GSK SPA with GGL, an affiliate of GSK, pursuant to which GGL purchased on the GSK Closing Date 7,450,000 shares of our common stock at a purchase price of approximately $1.20805 per share, for an aggregate purchase price of $9.0 million.

The GSK SPA contains certain standstill, lock-up and registration rights provisions.

Indemnification Agreements with Officers and Directors and Directors’ and Officers’ Liability Insurance

We have entered into indemnification agreements with each of our executive officers and directors.

The indemnification agreements, our Amended and Restated Certificate of Incorporation, as amended, and our Amended and Restated Bylaws require us to indemnify our directors to the fullest extent not prohibited by Delaware law.

Subject to certain limitations, our Amended and Restated Certificate of Incorporation, as amended, also requires us to advance expenses incurred by our directors and officers, subject to limited exceptions.

We also maintain a general liability insurance policy which covers certain liabilities of our directors and officers arising out of claims based on acts or omissions in their capacities as directors or officers.

Policies and Procedures for Related Party Transactions

We have adopted a written policy that requires all future transactions between us and any director, executive officer, holder of 5% or more of any class of our capital stock or any member of the immediate family of, or entities affiliated with, any of them, or any other related persons, as defined in Item 404 of Regulation S-K, or their affiliates, in which the amount involved is equal to or greater than the threshold amount proscribed by Item 404 of Regulation S-K, be approved in advance by our Audit Committee.

Any request for such a transaction must first be presented to our Audit Committee for review, consideration and approval.

In approving or rejecting any such proposal, our Audit Committee is to consider the relevant facts and circumstances available and deemed relevant to the Audit Committee, including, but not limited to, the extent of the related party’s interest in the transaction, and whether the

transaction is on terms no less favorable to us than terms we could have generally obtained from an unaffiliated third party under the same or similar circumstances.

Director Independence

Our Board of Directors undertook a review of the composition of our Board of Directors and independence of each director.

Based upon information requested from and provided by each director concerning his or her background, employment and affiliations, including family relationships, our Board of Directors has determined that each of Milind Deshpande, Ph.D., Scott Jackson, John C.

Pottage, Jr., M.D., Cynthia Smith, Frank E.

Thomas, Kathleen Tregoning and Patrick Vink, M.D.

would qualify as “independent” as that term is defined by Nasdaq Listing Rule 5605(a)(2).

Satyavrat Shukla would not qualify as “independent” under applicable Nasdaq Listing Rules applicable to the Board of Directors generally or to separately designated Board committees because he currently serves as our Chief Executive Officer.

Additionally, Ankit Mahadevia, M.D.

would not qualify as “independent” under applicable Nasdaq Listing Rules applicable to the Board of Directors generally or to separately designated Board committees because he previously served as our Chief Executive Officer within the past three years.

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

The response to this item is incorporated by reference from the discussion responsive thereto under the captions “Certain Relationships and Related Transactions” and “Management and Corporate Governance Matters” in our proxy statement for the 2025 Annual Meeting of Stockholders to be filed with the SEC within 120 days after the end of the fiscal year covered by this Annual Report on Form 10-K.

Principal Accountant Fees and Services.

PricewaterhouseCoopers LLP was our independent registered public accounting firm for the fiscal years ended December 31, 2023 and 2022.

The following table presents fees for professional audit services and other services rendered by PricewaterhouseCoopers LLP to us for the fiscal years ended December 31, 2023 and December 31, 2022:

Fiscal Year 2023

Fiscal Year 2022

Audit Fees(1)

Audit-Related Fees(2)

All Other Fees(3)

Audit fees consisted of audit work performed in the preparation of financial statements, the review of the interim consolidated financial statements, and related services that are normally provided in connection with registration statements.

Audit related fees consist of fees billed by PricewaterhouseCoopers LLP for assurance and related services that are reasonably related to the performance of the audit or review of our consolidated financial statements.

All other fees represent payment for access to the PricewaterhouseCoopers LLP online accounting research and financial disclosure databases.

Policy on Audit Committee Pre-Approval of Services

Consistent with SEC policies regarding auditor independence, the Audit Committee has responsibility for appointing, setting compensation and overseeing the work of our independent registered public accounting firm.

In recognition of this responsibility, the Audit Committee reviews and pre-approves all audit and permissible non-audit services provided by our independent registered public accounting firm;

provided, however, that de minimis non-audit services may instead be approved in accordance with applicable SEC rules.

The response to this item is incorporated by reference from the discussion responsive thereto under the caption “Independent Public Accountants” in our proxy statement for the 2025 Annual Meeting of Stockholders to be filed with the SEC within 120 days after the end of the fiscal year covered by this Annual Report on Form 10-K.

Exhibits, Financ ial Statement Schedules.

32 unchanged sentences

2019 Inducement Equity Incentive Plan, as amended

(Exhibit 10.4)

Form of Stock Option Agreement under the 2019 Inducement Equity Incentive Plan, as amended

5 unchanged sentences

Non-Employee Director Compensation Policy, as amended

(Exhibit 10.8)

Consulting Agreement, dated June 13, 2023, by and between the Registrant and Ankit Mahadevia, M.D.

(Exhibit 10.2)

Amended and Restated Employment Agreement, dated June 13, 2023, by and between the Registrant and Satyavrat Shukla

Amendment and Restated Employment Agreement, dated June 13, 2023, by and between the Registrant and Satyavrat Shukla

(Exhibit 10.3)

Employment Agreement, dated August 11, 2022, by and between the Registrant and Kamal Hamed

Interim Period Agreement, dated January 10, 2025, by and between the Registrant and Satyavrat Shukla

(Exhibit 10.1)

Retention Letter Agreement, dated November 13, 2024, by and between the Registrant and Satyavrat Shukla

Employment Agreement, dated August 11, 2022, by and between the Registrant and Kamal Hamed, M.D.

(Exhibit 10.5)

Amendment to Employment Agreement, dated November 10, 2022, by and between the Registrant and Kamal Hamed, M.D.

(Exhibit 10.8)

Employment Agreement, dated January 1, 2020, by and between the Registrant and Timothy Keutzer

Separation Agreement, dated July 30,2024 by and between the Registrant and Kamal Hamed, M.D.

(Exhibit 10.1)

Separation Agreement, dated July 30,2024 by and between the Registrant and Kamal Hamed, M.D.

(Exhibit 10.12)

Amendment to Employment Agreement, dated November 10, 2022, by and between the Registrant and Timothy Keutzer

2 unchanged sentences

(Exhibit 10.1)

Retention Letter Agreement, dated November 13, 2024, by and between the Registrant and Timothy Keutzer

Employment Agreement, dated October 31, 2023 by and between the Registrant and Esther Rajavelu

(Exhibit 10.1)

Interim Period Agreement, dated January 10, 2025, by and between the Registrant and Esther Rajavelu

(Exhibit 10.2)

Retention Letter Agreement, dated November 13, 2024, by and between the Registrant and Esther Rajavelu

Employment Agreement, dated November 6, 2020, by and between the Registrant and Tamara Joseph

3 unchanged sentences

Separation Agreement, dated February 9, 2024, by and between the Registrant and Tamara Joseph

(Exhibit 10.34)

Consulting Agreement, dated February 9, 2024, by and between the Registrant and Tamara Joseph

(Exhibit 10.34)

Consulting Agreement, effective as of August 5, 2024, by and between the Registrant and John C.

Pottage, Jr., M.D.

(Exhibit 10.3)

Amended and Restated Consulting Agreement, effective as of January 29, 2025, by and between the Registrant and John C.

Pottage, Jr., M.D.

Lease Agreement, dated August 24, 2015, by and between the Registrant and U.S.

22 unchanged sentences

(Exhibit 10.25)

Exchange Agreement, dated November 15, 2018, by and among the Registrant and Biotechnology Value Fund, L.P., Biotechnology Value Fund II, L.P., Biotechnology Value Trading Fund OS, L.P.

and MSI BVF SPV LLC

(Exhibit 10.1)

License Agreement, dated June 30, 2021, by and between the Registrant and Pfizer Inc.

5 unchanged sentences

Amendment 1 to Exclusive License Agreement, dated July 4, 2023, by and between the Registrant and GlaxoSmithKline Intellectual Property (No.

(Exhibit 10.34)

Amendment 2 to Exclusive License Agreement, dated December 20, 2023, by and between the Registrant and GlaxoSmithKline Intellectual Property (No.

(Exhibit 10.34)

Amendment 3 to Exclusive License Agreement, dated March 4, 2024, by and between the Registrant and GlaxoSmithKline Intellectual Property (No.

(Exhibit 10.4)

Amendment 4 to Exclusive License Agreement, dated October 28, 2024, by and between the Registrant and GlaxoSmithKline Intellectual Property (No.

(Exhibit 10.3)

Share Purchase Agreement, dated September 21, 2022, by and between the Registrant and Glaxo Group Limited

4 unchanged sentences

(Exhibit 10.17)

Spero Therapeutics, Inc.

Insider Trading Policy, effective as of June 5, 2023

List of Subsidiaries of the Registrant

6 unchanged sentences

Clawback Policy, effective as of November 12, 2023

(Exhibit 97.1)

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

15 unchanged sentences

March 27, 2025

/s/ Satyavrat Shukla

Satyavrat Shukla

President and Chief Executive Officer

/s/ Esther Rajavelu

Esther Rajavelu

Interim Chief Executive Office

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints each of Satyavrat Shukla and Esther Rajavelu his or her true and lawful attorney-in-fact and agent, with full power of substitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any and all amendments to this Annual Report on Form 10-K, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorney-in-fact and agent, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agent, or his substitutes or substitute, may lawfully do or cause to be done by virtue hereof.

IN WITNESS WHEREOF, each of the undersigned has executed this Power of Attorney as of the date indicated opposite his or her name.

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Esther Rajavelu or her true and lawful attorney-in-fact and agent, with full power of substitution, for her and in her name, place and stead, in any and all capacities, to sign any and all amendments to this Annual Report on Form 10-K, and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorney-in-fact and agent, full power and authority to do and perform each and every act and thing requisite and necessary to be done in connection therewith, as fully to all intents and purposes as she might or could do in person, hereby ratifying and confirming all that said attorney-in-fact and agent, or her substitutes or substitute, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant in the capacities and on the dates indicated.

/s/ Satyavrat Shukla

President, Chief Executive Officer and Director

March 13, 2024

Satyavrat Shukla

(Principal Executive Officer)

/s/ Esther Rajavelu

Chief Financial Officer, Chief Business Officer and Treasurer

Interim Chief Executive Officer, Chief Financial Officer, Chief Business Officer and Treasurer

March 27, 2025

Esther Rajavelu

(Principal Financial Officer and Principal Accounting Officer)

(Principal Executive, Financial and Accounting Officer)

/s/ Milind Deshpande, Ph.D.

4 unchanged sentences

Scott Jackson

/s/ Ankit Mahadevia, M.D.

March 13, 2024

Ankit Mahadevia, M.D.

Pottage, M.D.

12 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