16 unchanged sentences
Management’s Annual Report on Internal Control over Financial Reporting
−Removed: This Annual Report does not include a report of management's assessment regarding internal controls over financial reporting due to a transition period established by rules of the SEC for newly public companies.
+Added: Management is responsible for establishing and maintaining adequate internal control over financial reporting, as defined in Rules 13a-15(f) and 15d-15(f) under the Securities Exchange Act of 1934, as amended.
+Added: Management, with the participation of our Chief Executive Officer and our Chief Financial Officer, conducted an evaluation of the effectiveness of the Company’s internal control over financial reporting as of December 31, 2025 based on the criteria established in Internal Control— Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission.
+Added: Our internal control system was designed to provide reasonable assurance to our management and our Board regarding the preparation and fair presentation of published financial statements.
+Added: All internal control systems, no matter how well designed, have inherent limitations.
+Added: Therefore, even those systems determined to be effective can provide only reasonable assurance with respect to financial statement preparation and presentation.
+Added: Based on this evaluation, management concluded that the Company’s internal control over financial reporting was effective as of December 31, 2025.
Attestation Report of the Registered Public Accounting Firm
−Removed: This Annual Report does not include an attestation report of our registered public accounting firm due to a transition period established by rules of the SEC for newly public companies.
−Removed: Additionally, our independent registered public accounting firm will not be required to opine on our internal controls over financial reporting due to an exemption established by the JOBS Act for "emerging growth companies".
+Added: This Annual Report does not include an attestation report of the Company’s independent registered public accounting firm regarding internal control over financial reporting.
+Added: Management’s assessment was not subject to attestation by the Company’s independent registered public accounting firm pursuant to the exemption provided to emerging growth companies under the Jumpstart Our Business Startups Act of 2012, as amended.
Changes in Internal Control Over Financial Reporting
22 unchanged sentences
3.1 Fifth Amended and Restated Certificate of Incorporation of Sionna Therapeutics, Inc.
−Removed: (Incorporated by r eference to Exhibit 3.1 of the Registrant’s Current Report on Form 8-K (File No.
+Added: (Incorporated by reference to Exhibit 3.1 of the Registrant’s Current Report on Form 8-K (File No.
001-42504) filed on February 10, 2025).
3.2 Amended and Restated Bylaws of Sionna Therapeutics, Inc.
−Removed: (Incorporated by r eference to Exhibit 3.2 of the Registrant’s Current Report on Form 8-K (File No.
+Added: (Incorporated by reference to Exhibit 3.2 of the Registrant’s Current Report on Form 8-K (File No.
001-42504) filed on February 10, 2025).
−Removed: 4.1 Specimen Common Stock Certificate (Incorporated by r eference to Exhibit 4.1 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: 4.1 Specimen Common Stock Certificate (Incorporated by reference to Exhibit 4.1 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025).
−Removed: Third Amended and Restated Investors’ Rights Agreement, by and between the Registrant and certain of its stockholders, dated as of March 4, 2024 (Incorporated by r eference to Exhibit 4.2 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: Third Amended and Restated Investors’ Rights Agreement, by and between the Registrant and certain of its stockholders, dated as of March 4, 2024 (Incorporated by reference to Exhibit 4.2 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025) .
−Removed: Description of Securities of the Regist rant .
−Removed: 2020 Stock Option and Grant Plan and form of award agreements thereunder (Incorporated by r eference to Exhibit 10.1 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: 4.3 Description of Securities of the Registrant (Incorporated by reference to Exhibit 4.3 of the Registrant ' s Annual Report on Form 10-K (File No.
+Added: 001-42504) filed on M arch 20, 2025 ) .
+Added: 2020 Stock Option and Grant Plan and form of award agreements thereunder (Incorporated by reference to Exhibit 10.1 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025) .
Sionna Therapeutics, Inc.
−Removed: 2025 Stock Option and Incentive Plan and form of award agreements thereunder (Incorporated by r eference to Exhibit 10.2 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: 2025 Stock Option and Incentive Plan and form of award agreements thereunder (Incorporated by reference to Exhibit 10.2 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025) .
Sionna Therapeutics, Inc.
−Removed: 2025 Employee Stock Purchase Plan (Incorporated by r eference to Exhibit 10.3 of the Registrant’s Registration Statement on Form S-1/A (File No.
−Removed: 333-284352) filed on February 3, 2025) .
−Removed: Form of Indemnification Agreement by and between the Registrant and its director and executive officers (Incorporated by r eference to Exhibit 10.4 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: 2025 Employee Stock Purchase Plan (Incorporated by reference to Exhibit 10.3 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025) .
−Removed: Senior Executive Cash Incentive Bonus Plan (Incorporated by r eference to Exhibit 10.5 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: Form of Indemnification Agreement by and between the Registrant and its director s and executive officers (Incorporated by reference to Exhibit 10.4 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025) .
−Removed: Severance and Change in Control Plan (Incorporated by r eference to Exhibit 10.6 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: Senior Executive Cash Incentive Bonus Plan (Incorporated by reference to Exhibit 10.5 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025).
−Removed: Non-Employee Director Compensation Policy (Incorporated by r eference to Exhibit 10.7 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: Severance and Change in Control Plan (Incorporated by reference to Exhibit 10.6 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025).
−Removed: License Agreement by and between the Registrant and Sanofi Genzyme, dated as of December 20, 2019, as amended (Incorporated by r eference to Exhibit 10.9 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: Amended and Restated Non-Employee Director Compensation Policy.
+Added: License Agreement by and between the Registrant and Sanofi Genzyme, dated as of December 20, 2019, as amended (Incorporated by reference to Exhibit 10.9 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025) .
Number Description
−Removed: License Agreement by and between the Registrant and AbbVie Global Enterprises Ltd., dated as of July 11, 2024 (Incorporated by r eference to Exhibit 10.10 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: License Agreement by and between the Registrant and AbbVie Global Enterprises Ltd., dated as of July 11, 2024 (Incorporated by reference to Exhibit 10.10 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025) .
−Removed: Payment Agreement by and between the Registrant and Cystic Fibrosis Foundation, dated as of December 20, 2019 (Incorporated by r eference to Exhibit 10.11 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: Payment Agreement by and between the Registrant and Cystic Fibrosis Foundation, dated as of December 20, 2019 (Incorporated by reference to Exhibit 10.11 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025) .
−Removed: Offer Letter by and between the Registrant and Michael Cloonan, dated as of March 8, 2021 (Incorporated by r eference to Exhibit 10.12 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: Offer Letter by and between the Registrant and Michael Cloonan, dated as of March 8, 2021 (Incorporated by reference to Exhibit 10.12 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025) .
−Removed: Offer Letter by and between the Registrant and Charlotte McKee, dated as of May 7, 2021 (Incorporated by r eference to Exhibit 10.13 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: Offer Letter by and between the Registrant and Charlotte McKee, dated as of May 7, 2021 (Incorporated by reference to Exhibit 10.13 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025) .
−Removed: Offer Letter by and between the Registrant and Elena Ridloff, dated as of August 20, 2021 (Incorporated by r eference to Exhibit 10.14 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: Offer Letter by and between the Registrant and Elena Ridloff, dated as of August 20, 2021 (Incorporated by reference to Exhibit 10.14 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025) .
−Removed: Lease by and between the Registrant and BP3-BOS6 21 Hickory LLC, dated as of May 18, 2022, as amended (Incorporated by r eference to Exhibit 10.15 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: Lease by and between the Registrant and BP3-BOS6 21 Hickory LLC, dated as of May 18, 2022, as amended (Incorporated by reference to Exhibit 10.15 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025) .
−Removed: S ionna Therapeutics , Inc.
−Removed: Ins ider Trading Policy .
−Removed: 21.1 Subsidiaries of Registrant (Incorporated by r eference to Exhibit 21.1 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: 19.1 Sionna Therapeutics, Inc.
+Added: Insider Trading Policy (Incorporated by reference to Exhibit 19.1 of the Registrant's Annual Report on Form 10-K (File No.
+Added: 001-42504) filed on March 20, 2025) .
+Added: 21.1 Subsidiaries of Registrant (Incorporated by reference to Exhibit 21.1 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025) .
4 unchanged sentences
Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
−Removed: 97.1 Compensation R eco very P olicy ( Incorporated by r eference to Exhibit 10.8 of the Registrant’s Registration Statement on Form S-1/A (File No.
+Added: 97.1 Compensation Recovery Policy (Incorporated by reference to Exhibit 10.8 of the Registrant’s Registration Statement on Form S-1/A (File No.
333-284352) filed on February 3, 2025).
22 unchanged sentences
/s/ Elena Ridloff
−Removed: Chief Financial Officer and Head of Corporate Development ( Principal Financial Officer and Principal Accounting Officer )
+Added: Chief Financial Officer ( Principal Financial Officer and Principal Accounting Officer )
March 2, 2026
6 unchanged sentences
Bruce Booth, D.Phil.
−Removed: Edward Fleming
+Added: Edward Fleming, Jr.
Director March 2, 2026
7 unchanged sentences
Signature Title Date
+Added: /s/ Marcella K.
+Added: Ruddy Director March 2, 2026
/s/ Laurie Stelzer
3 unchanged sentences
Thompson, M.D.
−Removed: /s/ Marcella K.
−Removed: Director March 20, 2025
/s/ Joanne Viney
2 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.