KROS / Keros Therapeutics, Inc. - SEC-arkiveringar, Årsredovisning, Fullmaktsutlåtande

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 3, 2026 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 3, 2026 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission F

Keros Therapeutics Announces Participation at Goldman Sachs 47th Annual Global Healthcare Conference

Exhibit 99.1 Keros Therapeutics Announces Participation at Goldman Sachs 47th Annual Global Healthcare Conference LEXINGTON, Mass., June 1, 2026 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 1, 2026 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 1, 2026 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission F

KEROS THERAPEUTICS, INC. Condensed Consolidated Statements of Operations (In thousands, except share and per share data) THREE MONTHS ENDED MARCH 31, 2026 2025 REVENUE: Service and other revenue 367 15,891 License revenue — 195,355 Total revenue 367

Exhibit 99.1 Keros Therapeutics Reports Recent First Quarter 2026 Financial Results LEXINGTON, Mass., May 14, 2026 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional signaling of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 14, 2026 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 14, 2026 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2026 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39264 KEROS THE

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.       )

TABLE OF CONTENTS SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

ARS

2025 Annual Report NASDAQ: KROSUNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

Keros Therapeutics Presents Additional Clinical Data from Its Rinvatercept Program at the 2026 MDA Clinical & Scientific Conference

Exhibit 99.2 Keros Therapeutics Presents Additional Clinical Data from Its Rinvatercept Program at the 2026 MDA Clinical & Scientific Conference LEXINGTON, Mass., Mar. 9, 2026 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 9, 2026 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 9, 2026 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

Keros Therapeutics Announces Collaboration with Sean M. Healey & AMG Center for ALS

Exhibit 99.1 Keros Therapeutics Announces Collaboration with Sean M. Healey & AMG Center for ALS LEXINGTON, Mass., Mar. 9, 2026 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional

Subsidiaries of Keros Therapeutics, Inc.

Exhibit 21.1 Subsidiaries of Keros Therapeutics, Inc. Name of Subsidiary Jurisdiction of Organization Keros Therapeutics Australia, Pty Ltd Australia Keros Security Corporation Massachusetts

DESCRIPTION OF REGISTRANTS SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934

Exhibit 4.4 DESCRIPTION OF REGISTRANTS SECURITIES REGISTERED PURSUANT TO SECTION 12 OF THE SECURITIES EXCHANGE ACT OF 1934 The following description of the capital stock of Keros Therapeutics, Inc., or the Company, is a summary and does not purport to be complete. This summary is qualified in its entirety by reference to the provisions of the Delaware General Corporation Law, or the DGCL, and the

March 2026 Corporate Presentation Corporate Presentation Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of

corporatepresentationmar March 2026 Corporate Presentation Corporate Presentation Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended.

AMENDMENT TO EXECUTIVE EMPLOYMENT AGREEMENT

Exhibit 10.27 AMENDMENT TO EXECUTIVE EMPLOYMENT AGREEMENT This Amendment to Executive Employment Agreement (“Amendment”) is entered into by and between Keros Therapeutics, Inc. (“Company”) and Esther Cho (“Executive”) (each herein referred to individually as a “Party,” or collectively as the “Parties”) as of February 24, 2026 (“Effective Date”). Company and Executive entered into that certain Exec

KEROS THERAPEUTICS, INC. Consolidated Statements of Operations (In thousands, except share and per share data) THREE MONTHS ENDED DECEMBER 31, YEAR ENDED DECEMBER 31, 2025 2024 2025 2024 REVENUE: Service and other revenue 385 42 38,706 550 License re

Exhibit 99.1 Keros Therapeutics Reports Recent Business Highlights and Fourth Quarter and Full Year 2025 Financial Results LEXINGTON, Mass., March 4, 2026 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 4, 2026 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 4, 2026 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 4, 2026 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 4, 2026 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

As filed with the Securities and Exchange Commission on March 4, 2026

As filed with the Securities and Exchange Commission on March 4, 2026 Registration No.

Keros Therapeutics, Inc. Amended and Restated Non-Employee Director Compensation Policy

Exhibit 10.7 Keros Therapeutics, Inc. Amended and Restated Non-Employee Director Compensation Policy Each member of the Board of Directors (the “Board”) who is not also serving as an employee of or consultant to Keros Therapeutics, Inc. (the “Company”) or any of its subsidiaries (each such member, an “Eligible Director”) will receive the compensation described in this Amended and Restated Non-Empl

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39264 KEROS THERAPEU

AMENDMENT NO. 1 TO EXCLUSIVE LICENSE AGREEMENT

CERTAIN IDENTIFIED INFORMATION HAS BEEN EXCLUDED FROM THE EXHIBIT BECAUSE IT IS BOTH NOT MATERIAL AND WOULD LIKELY CAUSE COMPETITIVE HARM TO THE REGISTRANT IF PUBLICLY DISCLOSED.

Table 1: Newly Registered Securities

Calculation of Filing Fee Tables S-8 Keros Therapeutics, Inc. Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee 1 Equity 2020 Equity Incentive Plan, Common Stock, $0.0001 par value per share Other 781,748 $ 13.60 $ 10,631,772.80

Keros Therapeutics Appoints Charles Newton to its Board of Directors

Exhibit 99.1 Keros Therapeutics Appoints Charles Newton to its Board of Directors LEXINGTON, Mass., Feb. 26, 2026 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional signaling of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 20, 2026 Keros Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 20, 2026 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commiss

Keros Therapeutics Announces Participation at Upcoming Healthcare Conferences

Exhibit 99.1 Keros Therapeutics Announces Participation at Upcoming Healthcare Conferences LEXINGTON, Mass., Feb. 18, 2026 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional sign

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 18, 2026 Keros Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 18, 2026 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commiss

January 2026 Corporate Presentation Corporate Presentation Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act o

keros-corporatepresentat January 2026 Corporate Presentation Corporate Presentation Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 9, 2026 Keros Therapeutic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 9, 2026 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissio

Keros Therapeutics Announces Final Results of Tender Offer

Exhibit (a)(5)(D) Keros Therapeutics Announces Final Results of Tender Offer LEXINGTON, Mass.

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Amendment No. 2 to SCHEDULE TO TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1) OF THE SECURITIES EXCHANGE ACT OF 1934 Keros Therapeutics, Inc. (Name of Subject Company (Issuer)) Kero

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Amendment No. 2 to SCHEDULE TO TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1) OF THE SECURITIES EXCHANGE ACT OF 1934 Keros Therapeutics, Inc. (Name of Subject Company (Issuer)) Keros Therapeutics, Inc. (Names of Filing Persons (Issuer and Offeror)) Common Stock, $0.0001 par value per share (Title of Class of Securities) 492327101

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Amendment No. 1 to SCHEDULE TO TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1) OF THE SECURITIES EXCHANGE ACT OF 1934 Keros Therapeutics, Inc. (Name of Subject Company (Issuer)) Kero

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Amendment No. 1 to SCHEDULE TO TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1) OF THE SECURITIES EXCHANGE ACT OF 1934 Keros Therapeutics, Inc. (Name of Subject Company (Issuer)) Keros Therapeutics, Inc. (Names of Filing Persons (Issuer and Offeror)) Common Stock, $0.0001 par value per share (Title of Class of Securities) 492327101

Keros Therapeutics Announces Preliminary Results of Tender Offer

Exhibit (a)(5)(C) Keros Therapeutics Announces Preliminary Results of Tender Offer LEXINGTON, Mass.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 5, 2025 Keros Therapeuti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 5, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39264 KEROS

KEROS THERAPEUTICS, INC. Condensed Consolidated Statements of Operations (In thousands, except share and per share data) THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, 2025 2024 2025 2024 REVENUE: Service and other revenue 4,262 388

Exhibit 99.1 Keros Therapeutics Reports Third Quarter 2025 Financial Results LEXINGTON, Mass., November 5, 2025 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional signaling of th

This announcement is neither an offer to purchase nor a solicitation of an offer to sell shares. The Offer (as defined below) is made solely by the Offer to Purchase, dated October 20, 2025, and the related Letter of Transmittal, and any amendments o

Exhibit (a)(1)(F) This announcement is neither an offer to purchase nor a solicitation of an offer to sell shares.

LETTER OF TRANSMITTAL TO TENDER SHARES OF COMMON STOCK PURSUANT TO THE OFFER TO PURCHASE DATED OCTOBER 20, 2025 by KEROS THERAPEUTICS, INC. of UP TO 10,950,165 SHARES OF ITS COMMON STOCK, AT A PURCHASE PRICE OF $17.75 PER SHARE

 Exhibit (a)(1)(B) LETTER OF TRANSMITTAL TO TENDER SHARES OF COMMON STOCK PURSUANT TO THE OFFER TO PURCHASE DATED OCTOBER 20, 2025 by KEROS THERAPEUTICS, INC.

Keros Therapeutics Commences Issuer Tender Offer to Repurchase up to $194.4 Million Shares

Exhibit (a)(5)(B) Keros Therapeutics Commences Issuer Tender Offer to Repurchase up to $194.

OFFER TO PURCHASE FOR CASH BY KEROS THERAPEUTICS, INC. UP TO 10,950,165 SHARES OF ITS COMMON STOCK, AT A PURCHASE PRICE OF $17.75 PER SHARE

 Exhibit (a)(1)(D) OFFER TO PURCHASE FOR CASH BY KEROS THERAPEUTICS, INC. OF UP TO 10,950,165 SHARES OF ITS COMMON STOCK, AT A PURCHASE PRICE OF $17.75 PER SHARE THE OFFER, PRORATION PERIOD AND WITHDRAWAL RIGHTS WILL EXPIRE AT 5:00 P.M., NEW YORK CITY TIME, ON TUESDAY, NOVEMBER 18, 2025 UNLESS THE OFFER IS EXTENDED (SUCH DATE AND TIME, AS THEY MAY BE EXTENDED, THE “EXPIRATION TIME”) OR TERMINATED.

OFFER TO PURCHASE FOR CASH BY Keros Therapeutics, Inc. UP TO 10,950,165 SHARES OF ITS COMMON STOCK, AT A PURCHASE PRICE OF $17.75 PER SHARE

TABLE OF CONTENTS  Exhibit (a)(1)(A) OFFER TO PURCHASE FOR CASH BY Keros Therapeutics, Inc.

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE TO TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1) OF THE SECURITIES EXCHANGE ACT OF 1934 Keros Therapeutics, Inc. (Name of Subject Company (Issuer)) Keros Therapeutics, Inc

SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE TO TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1) OF THE SECURITIES EXCHANGE ACT OF 1934 Keros Therapeutics, Inc. (Name of Subject Company (Issuer)) Keros Therapeutics, Inc. (Names of Filing Persons (Issuer and Offeror)) Common Stock, $0.0001 par value per share (Title of Class of Securities) 492327101 (CUSIP Number of C

NOTICE OF GUARANTEED DELIVERY (Not to be used for Signature Guarantee) for Tender of Common Stock KEROS THERAPEUTICS, INC. THE OFFER, PRORATION PERIOD AND WITHDRAWAL RIGHTS WILL EXPIRE AT 5:00 P.M., NEW YORK CITY TIME, ON TUESDAY, NOVEMBER 18, 2025,

 Exhibit (a)(1)(C) NOTICE OF GUARANTEED DELIVERY (Not to be used for Signature Guarantee) for Tender of Common Stock of KEROS THERAPEUTICS, INC.

Table 1: Transaction Valuation

Calculation of Filing Fee Tables Table 1: Transaction Valuation Transaction Valuation Fee Rate Amount of Filing Fee Fees to be Paid 1 $ 194,365,428.

OFFER TO PURCHASE FOR CASH BY KEROS THERAPEUTICS, INC. UP TO 10,950,165 SHARES OF ITS COMMON STOCK, AT A PURCHASE PRICE OF $17.75 PER SHARE THE OFFER, PRORATION PERIOD AND WITHDRAWAL RIGHTS WILL EXPIRE AT 5:00 P.M., NEW YORK CITY TIME, ON TUESDAY, NO

 Exhibit (a)(1)(E) OFFER TO PURCHASE FOR CASH BY KEROS THERAPEUTICS, INC. OF UP TO 10,950,165 SHARES OF ITS COMMON STOCK, AT A PURCHASE PRICE OF $17.75 PER SHARE THE OFFER, PRORATION PERIOD AND WITHDRAWAL RIGHTS WILL EXPIRE AT 5:00 P.M., NEW YORK CITY TIME, ON TUESDAY, NOVEMBER 18 , 2025 UNLESS THE OFFER IS EXTENDED (SUCH DATE AND TIME, AS THEY MAY BE EXTENDED, THE “EXPIRATION TIME”) OR TERMINATED

STOCK PURCHASE AGREEMENT

Exhibit 2.2 Execution Version STOCK PURCHASE AGREEMENT Stock Purchase Agreement (this “Agreement”), dated as of October 15, 2025 (the “Effective Date”), by and between Keros Therapeutics, Inc., a Delaware corporation (the “Company”), and the persons listed on Schedule I hereto (collectively, the “Seller Affiliates” and, together with the Company, each a “Party” and collectively, the “Parties”). Ce

STOCK PURCHASE AGREEMENT

Exhibit 2.1 EXECUTION VERSION STOCK PURCHASE AGREEMENT Stock Purchase Agreement (this “Agreement”), dated as of October 15, 2025 (the “Effective Date”), by and between Keros Therapeutics, Inc., a Delaware corporation (the “Company”), ADAR1 Capital Management, LLC, a Texas limited liability company (“ADAR1 Capital Management”), and the persons listed on Schedule I hereto (the “Seller Affiliates” an

Keros Therapeutics Announces Plan for Return of $375 Million in Excess Capital Agrees to Repurchase of All Shares Held By ADAR1 Capital Management and Pontifax Venture Capital Plans to Commence Tender Offer to Repurchase up to $194 Million of Additio

Exhibit 99.1 Keros Therapeutics Announces Plan for Return of $375 Million in Excess Capital Agrees to Repurchase of All Shares Held By ADAR1 Capital Management and Pontifax Venture Capital Plans to Commence Tender Offer to Repurchase up to $194 Million of Additional Shares LEXINGTON, Mass., October 15, 2025 – Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biop

STOCK PURCHASE AGREEMENT

Exhibit 2.1 EXECUTION VERSION STOCK PURCHASE AGREEMENT Stock Purchase Agreement (this “Agreement”), dated as of October 15, 2025 (the “Effective Date”), by and between Keros Therapeutics, Inc., a Delaware corporation (the “Company”), ADAR1 Capital Management, LLC, a Texas limited liability company (“ADAR1 Capital Management”), and the persons listed on Schedule I hereto (the “Seller Affiliates” an

Keros Therapeutics Announces Plan for Return of $375 Million in Excess Capital Agrees to Repurchase of All Shares Held By ADAR1 Capital Management and Pontifax Venture Capital Plans to Commence Tender Offer to Repurchase up to $194 Million of Additio

Exhibit 99.1 Keros Therapeutics Announces Plan for Return of $375 Million in Excess Capital Agrees to Repurchase of All Shares Held By ADAR1 Capital Management and Pontifax Venture Capital Plans to Commence Tender Offer to Repurchase up to $194 Million of Additional Shares LEXINGTON, Mass., October 15, 2025 – Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biop

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 15, 2025 Keros Therapeuti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 15, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissi

STOCK PURCHASE AGREEMENT

Exhibit 2.2 Execution Version STOCK PURCHASE AGREEMENT Stock Purchase Agreement (this “Agreement”), dated as of October 15, 2025 (the “Effective Date”), by and between Keros Therapeutics, Inc., a Delaware corporation (the “Company”), and the persons listed on Schedule I hereto (collectively, the “Seller Affiliates” and, together with the Company, each a “Party” and collectively, the “Parties”). Ce

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 15, 2025 Keros Therapeuti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 15, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissi

144

144 0001706040 XXXXXXXX LIVE 0001664710 Keros Therapeutics, Inc. 001-39264 1050 WALTHAM STREET, SUITE 302 LEXINGTON MA 02421 617-314-6297 Rovaldi Christopher Affiliate Common UBS Financial Services Inc. 11 Madison Avenue 4th Floor New York NY 10010 85306 1340157.26 40615414 09/12/2025 NASDAQ Common 09/12/2025 Exercise of Stock Options Issuer N 85306 09/12/2025 Cash Y 09/12/2025 08/12/2024 /s/ UBS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 8, 2025 Keros Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 8, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commiss

Keros Therapeutics Presents Additional Clinical Data from its KER-065 Program at the American Society of Bone and Mineral Research 2025 Annual Meeting

Exhibit 99.1 Keros Therapeutics Presents Additional Clinical Data from its KER-065 Program at the American Society of Bone and Mineral Research 2025 Annual Meeting LEXINGTON, Mass., September 8, 2025 – Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with diso

Keros Therapeutics Announces Participation at Upcoming Healthcare Conferences

Exhibit 99.1 Keros Therapeutics Announces Participation at Upcoming Healthcare Conferences LEXINGTON, Mass., Aug. 28, 2025 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional sign

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 28, 2025 Keros Therapeutic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 28, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 20, 2025 Keros Therapeutic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 20, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissio

Keros Announces U.S. FDA Orphan Drug Designation Granted to KER-065 for the Treatment of Duchenne Muscular Dystrophy

Exhibit 99.1 Keros Announces U.S. FDA Orphan Drug Designation Granted to KER-065 for the Treatment of Duchenne Muscular Dystrophy LEXINGTON, Mass., August 20, 2025 – Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunction

KEROS THERAPEUTICS, INC. Condensed Consolidated Statements of Operations (In thousands, except share and per share data) THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, 2025 2024 2025 2024 REVENUE: Service and other revenue 18,168 37 34,059 120

Exhibit 99.1 Keros Therapeutics Reports Second Quarter 2025 Financial Results LEXINGTON, Mass., August 6, 2025 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional signaling of the

Amended and Restated Non-Employee Director Compensation Policy

Exhibit 10.1 Keros Therapeutics, Inc. Amended and Restated Non-Employee Director Compensation Policy Each member of the Board of Directors (the “Board”) who is not also serving as an employee of or consultant to Keros Therapeutics, Inc. (the “Company”) or any of its subsidiaries (each such member, an “Eligible Director”) will receive the compensation described in this Amended and Restated Non-Empl

Employment Agreement by and between Keros Therapeutics, Inc. and Esther Cho, dated as of August 6, 2025.

Exhibit 10.3 EXECUTIVE EMPLOYMENT AGREEMENT THIS EXECUTIVE EMPLOYMENT AGREEMENT (this “Agreement”), by and between Keros Therapeutics, Inc. (the “Company”), and Esther Cho (“Executive”) (collectively referred to as the “Parties” or individually referred to as a “Party”), is effective as of August 6, 2025 (the “Effective Date”). R E C I T A L S WHEREAS, Executive has been employed by the Company on

Employment Agreement by and between Keros Therapeutics, Inc. and Lorena Lerner, dated as of August 6, 2025.

Exhibit 10.1 EXECUTIVE EMPLOYMENT AGREEMENT THIS EXECUTIVE EMPLOYMENT AGREEMENT (this “Agreement”), by and between Keros Therapeutics, Inc. (the “Company”), and Lorena Lerner (“Executive”) (collectively referred to as the “Parties” or individually referred to as a “Party”), is effective as of August 6, 2025 (the “Effective Date”). R E C I T A L S WHEREAS, on May 9, 2022, the Executive was employed

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 6, 2025 Keros Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 6, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

Separation and Release Agreement by and between Keros Therapeutics, Inc. and Christopher Rovaldi, dated as of August 6, 2025.

Exhibit 10.2 KEROS THERAPEUTICS, INC. 1050 Waltham Street, Suite 302 Lexington, Massachusetts 02421 August 6, 2025 Christopher Rovaldi [***] Re: Separation and Release Agreement Dear Chris: This letter sets forth the substance of the separation and release agreement (the “Agreement”) which Keros Therapeutics, Inc. (the “Company”) is offering to you to aid in your mutually agreed upon employment tr

Keros to Exclusively Prioritize the Clinical Advancement of KER-065 Company Discontinuing Development of Cibotercept (KER-012) Announces Board and Leadership Changes Designed to Support Streamlined Operational Structure and Strategic Realignment

Exhibit 99.1 Keros to Exclusively Prioritize the Clinical Advancement of KER-065 Company Discontinuing Development of Cibotercept (KER-012) Announces Board and Leadership Changes Designed to Support Streamlined Operational Structure and Strategic Realignment LEXINGTON, Mass., August 6, 2025 – Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on d

August 2025 Corporate Presentation Corporate Presentation Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of

keros-exhibit9928625 August 2025 Corporate Presentation Corporate Presentation Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 6, 2025 Keros Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 6, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39264 KEROS THER

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 17, 2025 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 17, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

Keros Therapeutics Announces the First Patient Dosing in the Phase 3 RENEW Clinical Trial of Elritercept

Exhibit 99.1 Keros Therapeutics Announces the First Patient Dosing in the Phase 3 RENEW Clinical Trial of Elritercept •Milestone payment of $10 million triggered under the global license agreement with Takeda LEXINGTON, Mass., July 17, 2025 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing nove

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 9, 2025 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 9, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission F

Keros Announces Return of $375 Million in Excess Capital to Stockholders Concludes Strategic Alternatives Review and Provides Update on Development of KER-065

Exhibit 99.1 Keros Announces Return of $375 Million in Excess Capital to Stockholders Concludes Strategic Alternatives Review and Provides Update on Development of KER-065 Lexington, Mass., June 9, 2025 – Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range o

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 4, 2025 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 4, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 6, 2025 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 6, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission F

Keros Therapeutics Announces Participation at Goldman Sachs 46

Exhibit 99.1 Keros Therapeutics Announces Participation at Goldman Sachs 46th Annual Global Healthcare Conference LEXINGTON, Mass., June 6, 2025 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional

Results from the Cibotercept TROPOS PAH Phase 2 Trial May 29, 2025 TROPOS Update Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities L

Results from the Cibotercept TROPOS PAH Phase 2 Trial May 29, 2025 TROPOS Update Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended.

Keros Therapeutics Announces TROPOS Topline Data and Corporate Restructuring Discontinues Development of Cibotercept in PAH Announces Corporate Restructuring to Align Operations with Ongoing Strategic Priorities

Exhibit 99.1 Keros Therapeutics Announces TROPOS Topline Data and Corporate Restructuring Discontinues Development of Cibotercept in PAH Announces Corporate Restructuring to Align Operations with Ongoing Strategic Priorities Lexington, Mass., May 29, 2025 – Keros Therapeutics, Inc. (“Keros”, the “Company” or “we”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 28, 2025 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 28, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant x Filed by a Party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Definitive Proxy State

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant x Filed by a Party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Definitive Proxy State

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant x Filed by a Party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Definitive Proxy State

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant x Filed by a Party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Definitive Proxy State

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 12, 2025 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 12, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission F

Keros Therapeutics Announces Participation at Bank of America 2025 Global Healthcare Conference

Exhibit 99.1 Keros Therapeutics Announces Participation at Bank of America 2025 Global Healthcare Conference LEXINGTON, Mass., May 12, 2025 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional sign

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant x Filed by a Party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Definitive Proxy State

KEROS THERAPEUTICS, INC. Condensed Consolidated Statements of Operations (In thousands, except share and per share data) THREE MONTHS ENDED MARCH 31, 2025 2024 REVENUE: Service and other revenue 15,891 83 License revenue 195,355 — Total revenue 211,2

Exhibit 99.1 Keros Therapeutics Reports Recent First Quarter 2025 Financial Results LEXINGTON, Mass., May 6, 2025 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional signaling of

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 6, 2025 Keros Therapeutics, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 6, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission Fi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39264 KEROS THE

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.       )

TABLE OF CONTENTS SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

ARS

2024 Annual Report NASDAQ: KROSUNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

Letter Agreement, dated April 17, 2025, by and between the Company and Pontifax

Exhibit 10.1 Keros Therapeutics, Inc. April 17, 2025 Pontifax (Israel) IV, L.P. Pontifax (Cayman) IV, L.P. Pontifax (China) IV, L.P. Pontifax Late Stage Fund L.P. c/o Pontifax 14 Shenkar Street, Beit Ofek Herzliya Pituach, 4672514 Israel Attention: Tomer Kariv and Ran Nussbaum Ladies and Gentlemen: Keros Therapeutics, Inc., a Delaware corporation (the “Company”), and Pontifax (Israel) IV, L.P., a

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 17, 2025 Keros Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 17, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

Certificate of Designation of Series A Junior Participating Preferred Stock filed with the Secretary of State of the State of Delaware on April 9, 2025

Exhibit 3.1 CERTIFICATE OF DESIGNATION OF RIGHTS, PREFERENCES AND PRIVILEGES OF SERIES A JUNIOR PARTICIPATING PREFERRED STOCK OF KEROS THERAPEUTICS, INC. The undersigned, Keith Regnante, does hereby certify: 1. That he is duly elected and acting Chief Financial Officer of Keros Therapeutics, Inc. a Delaware corporation (the “Corporation”). 2. That pursuant to the authority conferred upon the Board

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 Keros Therapeutics, Inc. (Exact name of Registr

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934 Keros Therapeutics, Inc. (Exact name of Registrant as specified in its charter) Delaware 81-1173868 (State of other jurisdiction of incorporation or organization) (I.R.S. Employer I.D. No.) 1050 Wa

Keros Therapeutics Announces Review of Strategic Alternatives

Exhibit 99.1 Keros Therapeutics Announces Review of Strategic Alternatives •Adopts Limited-Duration Stockholder Rights Plan to Protect Integrity of Process LEXINGTON, Mass., Apr. 10, 2025 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 9, 2025 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 9, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

and Computershare Trust Company, N.A., which includes the form of Certificate of Designation as Exhibit A, the form of Right Certificate as Exhibit B

Exhibit 4.1 RIGHTS AGREEMENT April 9, 2025 TABLE OF CONTENTS Page SECTION 1. CERTAIN DEFINITIONS 1 SECTION 2. APPOINTMENT OF RIGHTS AGENT 8 SECTION 3. ISSUANCE OF RIGHTS 8 SECTION 4. FORM OF RIGHT CERTIFICATES 11 SECTION 5. COUNTERSIGNATURE AND REGISTRATION 11 SECTION 6. TRANSFER, SPLIT UP, COMBINATION AND EXCHANGE OF RIGHT CERTIFICATES; MUTILATED, DESTROYED, LOST OR STOLEN RIGHT CERTIFICATES 12 S

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 31, 2025 Keros Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 31, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

KER-065 Update March 2025 KER-065 Update Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended

KER-065 Update March 2025 KER-065 Update Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended.

Keros Therapeutics Announces Initial Topline Results from the Phase 1 Clinical Trial of KER-065 in Healthy Volunteers

Exhibit 99.1 Keros Therapeutics Announces Initial Topline Results from the Phase 1 Clinical Trial of KER-065 in Healthy Volunteers •Trial achieved key objectives for safety, tolerability, pharmacokinetics and pharmacodynamics •Clinical data from this trial, together with preclinical data, support the therapeutic potential of KER-065 for broad impact in Duchenne muscular dystrophy (“DMD”) and other

Amended and Restated Bylaws of the Registrant.

Exhibit 3.1 AMENDED AND RESTATED BYLAWS OF KEROS THERAPEUTICS, INC. (A DELAWARE CORPORATION) March 5, 2025 TABLE OF CONTENTS Page Article I OFFICES 1 Section 1. Registered Office 1 Section 2. Other Offices 1 Article II CORPORATE SEAL 1 Section 3. Corporate Seal 1 Article III STOCKHOLDERS’ MEETINGS 1 Section 4. Place of Meetings 1 Section 5. Annual Meetings 1 Section 6. Special Meetings 8 Section 7

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 5, 2025 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 5, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 28, 2025 Keros Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 28, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commiss

Keros Therapeutics Announces Participation at Upcoming Healthcare Conferences

Exhibit 99.1 Keros Therapeutics Announces Participation at Upcoming Healthcare Conferences LEXINGTON, Mass., February 28, 2025 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional signaling of the

Pharmaceuticals U.S.A., Inc., dated as of December 3, 2024.

CERTAIN IDENTIFIED INFORMATION HAS BEEN EXCLUDED FROM THE EXHIBIT BECAUSE IT IS BOTH NOT MATERIAL AND WOULD LIKELY CAUSE COMPETITIVE HARM TO THE REGISTRANT IF PUBLICLY DISCLOSED.

Insider Trading Policy.

Exhibit 19 Keros Therapeutics, Inc. Insider Trading Policy I.Introduction During the course of your employment or directorship with Keros Therapeutics, Inc. (the “Company”), you may receive important information that is not yet publicly available (“inside information”) about the Company or about other publicly traded companies with which the Company has business dealings. Because of your access to

Forms of Stock Option Grant Notice, Option Agreement, Notice of Exercise, Restricted Stock Unit Grant Notice and Restricted Stock Unit Award Agreement for the 2020 Equity Incentive Plan.

Exhibit 10.5 Keros Therapeutics, Inc. Stock Option Grant Notice (2020 Equity Incentive Plan) Keros Therapeutics, Inc. (the “Company”), pursuant to its 2020 Equity Incentive Plan (the “Plan”), has granted to you (“Optionholder”) an option to purchase the number of shares of the Common Stock set forth below (the “Option”). Your Option is subject to all of the terms and conditions as set forth herein

KEROS THERAPEUTICS, INC. Consolidated Statements of Operations (In thousands, except share and per share data) THREE MONTHS ENDED DECEMBER 31, YEAR ENDED DECEMBER 31, 2024 2023 2024 2023 REVENUE: Service and other revenue 42 143 550 151 License reven

Exhibit 99.1 Keros Therapeutics Reports Recent Business Highlights and Fourth Quarter and Full Year 2024 Financial Results LEXINGTON, Mass., February 26, 2025 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders t

Subsidiaries of Keros Therapeutics, Inc.

Exhibit 21.1 Subsidiaries of Keros Therapeutics, Inc. Name of Subsidiary Jurisdiction of Organization Keros Therapeutics Australia, Pty Ltd Australia Keros Security Corporation Massachusetts

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39264 KEROS THERAPEU

Description of the Registrant’s Securities.

Exhibit 4.3 DESCRIPTION OF KEROS THERAPEUTICS, INC. COMMON STOCK The following description of the common stock of Keros Therapeutics, Inc., or the Company, is a summary and does not purport to be complete. This summary is qualified in its entirety by reference to the provisions of the Delaware General Corporation Law, or the DGCL, and the complete text of the Company’s amended and restated certifi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 26, 2025 Keros Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 26, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commiss

Filing fee table.

Calculation of Filing Fee Tables S-8 Keros Therapeutics, Inc. Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee 1 Equity 2020 Equity Incentive Plan, Common Stock, $0.0001 par value per share Other 1,622,188 $ 10.8536 $ 17,606,579

As filed with the Securities and Exchange Commission on February 26, 2025

As filed with the Securities and Exchange Commission on February 26, 2025 Registration No.

Incentive Compensation Recoupment Policy.

Exhibit 97 KEROS THERAPEUTICS, INC. INCENTIVE COMPENSATION RECOUPMENT POLICY 1. Introduction The Board of Directors (the “Board”) of Keros Therapeutics, Inc., a Delaware corporation (the “Company”), has determined that it is in the best interests of the Company and its stockholders to adopt this Incentive Compensation Recoupment Policy (this “Policy”) providing for the Company’s recoupment of Reco

EX-99

EX-99 2 exhibit99.txt Exhibit 99 Pursuant to the instructions in Item 7 of Schedule 13G, the following table lists the identity and Item 3 classification, if applicable, of each relevant entity that beneficially owns shares of the security class being reported on this Schedule 13G. Entity ITEM 3 Classification Fidelity Management & Research Company LLC IA Abigail P. Johnson is a Director, the Chai

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 30, 2025 Keros Therapeuti

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 30, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissi

Keros Therapeutics to Present at the Guggenheim SMID Cap Biotech Conference

Exhibit 99.1 Keros Therapeutics to Present at the Guggenheim SMID Cap Biotech Conference LEXINGTON, Mass., January 30, 2025 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional signaling of the tra

Keros Therapeutics Announces Effectiveness of Global License Agreement with Takeda to Advance Elritercept

Exhibit 99.1 Keros Therapeutics Announces Effectiveness of Global License Agreement with Takeda to Advance Elritercept LEXINGTON, Mass., Jan. 21, 2025 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 16, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissi

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 15, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissi

Keros Therapeutics Announces Additional Update on the Phase 2 TROPOS Trial

Exhibit 99.1 Keros Therapeutics Announces Additional Update on the Phase 2 TROPOS Trial LEXINGTON, Mass., Jan. 15, 2025 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional signali

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 10, 2025 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissi

January 2025 Corporate Presentation Corporate Presentation Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act o

January 2025 Corporate Presentation Corporate Presentation Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 12, 2024 Keros Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 12, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commiss

Keros Therapeutics Announces Update on the Phase 2 TROPOS Trial

Exhibit 99.1 Keros Therapeutics Announces Update on the Phase 2 TROPOS Trial •Keros will host an update call and webcast today, December 12, 2024, at 8:00 a.m. ET LEXINGTON, Mass., Dec. 12, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wid

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 9, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissi

Keros Therapeutics Presents Clinical Data from its Elritercept Program at the 66th American Society of Hematology Annual Meeting and Exposition

Exhibit 99.1 Keros Therapeutics Presents Clinical Data from its Elritercept Program at the 66th American Society of Hematology Annual Meeting and Exposition •Elritercept demonstrated a durable transfusion independence in lower-risk myelodysplastic syndromes, including in patients with high transfusion burden, with a median duration of response of 134.1 weeks •Durable clinical responses were associ

Keros Therapeutics Announces Global License Agreement with Takeda to Advance Elritercept

Exhibit 99.1 Keros Therapeutics Announces Global License Agreement with Takeda to Advance Elritercept Keros Therapeutics to receive upfront payment of $200 million and is eligible to receive development, approval and commercial milestone payments with the potential to exceed $1.1 billion and tiered royalties on net sales LEXINGTON, Mass., December 3, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 3, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissi

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 26, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commiss

Keros Therapeutics Announces Participation at Upcoming Healthcare Conferences

Exhibit 99.1 Keros Therapeutics Announces Participation at Upcoming Healthcare Conferences LEXINGTON, Mass., Nov. 26, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional sign

Keros Therapeutics to Present at the Guggenheim Healthcare Innovation Conference

Exhibit 99.1 Keros Therapeutics to Present at the Guggenheim Healthcare Innovation Conference LEXINGTON, Mass., November 6, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel treatments to treat a wide range of patients with disorders that are linked to dysfunctio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39264 KEROS

KEROS THERAPEUTICS, INC. Condensed Consolidated Statements of Operations (In thousands, except share and per share data) THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, 2024 2023 2024 2023 REVENUE: Service and other revenue 388 8 508

Exhibit 99.1 Keros Therapeutics Reports Recent Business Highlights and Third Quarter 2024 Financial Results LEXINGTON, Mass., November 6, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked t

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 6, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissi

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 6, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissi

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 15, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissi

Keros Therapeutics Appoints Yung H. Chyung, M.D., as Chief Medical Officer

Exhibit 99.1 Keros Therapeutics Appoints Yung H. Chyung, M.D., as Chief Medical Officer LEXINGTON, Mass., October 16, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional sign

Employment Agreement by and between Keros Therapeutics, Inc. and Yung H. Chyung, dated as of October

Exhibit 10.1 EXECUTIVE EMPLOYMENT AGREEMENT THIS EXECUTIVE EMPLOYMENT AGREEMENT (this “Agreement”), by and between Keros Therapeutics, Inc. (the “Company”), and Yung H. Chyung (“Executive”) (collectively referred to as the “Parties” or individually referred to as a “Party”), is effective as of November 1, 2024 (the “Effective Date”). R E C I T A L S WHEREAS, the Company desires to employ Executive

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 30, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commis

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 3, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commiss

Keros Therapeutics Announces Update on Enrollment in the Phase 2 TROPOS Trial

Exhibit 99.1 Keros Therapeutics Announces Update on Enrollment in the Phase 2 TROPOS Trial LEXINGTON, Mass., Sept. 3, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional sign

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 28, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissio

Keros Therapeutics Announces Participation at Upcoming Healthcare Conferences

Exhibit 99.1 Keros Therapeutics Announces Participation at Upcoming Healthcare Conferences LEXINGTON, Mass., Aug. 28, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional sign

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 7, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

Amended and Restated Non-Employee Director Compensation Policy

Exhibit 10.1 Keros Therapeutics, Inc. Amended and Restated Non-Employee Director Compensation Policy Each member of the Board of Directors (the “Board”) who is not also serving as an employee of or consultant to Keros Therapeutics, Inc. (the “Company”) or any of its subsidiaries (each such member, an “Eligible Director”) will receive the compensation described in this Amended and Restated Non-Empl

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39264 KEROS THER

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 7, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

August 2024 Corporate Presentation Corporate Presentation Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of

August 2024 Corporate Presentation Corporate Presentation Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended.

KEROS THERAPEUTICS, INC. Condensed Consolidated Statements of Operations (In thousands, except share and per share data) THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, 2024 2023 2024 2023 REVENUE: Service and other revenue 37 — 120 — Total rev

Exhibit 99.1 Keros Therapeutics Reports Second Quarter 2024 Financial Results LEXINGTON, Mass., August 7, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional signaling of the

Keros Therapeutics Announces Leadership Updates

Exhibit 99.1 Keros Therapeutics Announces Leadership Updates LEXINGTON, Mass., June 17, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel treatments to treat a wide range of patients with disorders that are linked to dysfunctional signaling of the tr

Sales Agreement, dated May 3, 2021, by and between the Registrant and Leerink Partners (formerly SVB Leerink LLC)

Exhibit 1.1 Keros Therapeutics, Inc. Shares of Common Stock ($0.0001 par value per share) SALES AGREEMENT May 3, 2021 SVB LEERINK LLC 1301 Avenue of the Americas, 12th Floor New York, New York 10019 Ladies and Gentlemen: Keros Therapeutics, Inc., a Delaware corporation (the “Company”), confirms its agreement (this “Agreement”) with SVB Leerink LLC (the “Agent”), as follows: 1. Issuance and Sale of

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 17, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 14, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

Corporate Update June 2024 June 2024 Corporate Update Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 199

Corporate Update June 2024 June 2024 Corporate Update Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended.

Calculation of Filing Fee Tables Form S-3 (Form Type) Keros Therapeutics, Inc. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities

Exhibit 107 Calculation of Filing Fee Tables Form S-3 (Form Type) Keros Therapeutics, Inc.

Keros Therapeutics Presents Clinical Data from its Elritercept (KER-050) Program at the 29th Annual Hybrid Congress of the European Hematology Association

Exhibit 99.1 Keros Therapeutics Presents Clinical Data from its Elritercept (KER-050) Program at the 29th Annual Hybrid Congress of the European Hematology Association •Elritercept continued to demonstrate a durable transfusion independence in lower-risk myelodysplastic syndromes, including in patients with high transfusion burden •Durable clinical responses were associated with improvements in pa

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 17, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

Up to $350,000,000 Common Stock

Filed Pursuant to Rule 424(b)(5) Registration No. 333-279094 PROSPECTUS SUPPLEMENT (To Prospectus dated May 3, 2024) Up to $350,000,000 Common Stock We have previously entered into a sales agreement, or the sales agreement, with Leerink Partners LLC, or Leerink Partners, dated May 3, 2021, pursuant to which we may offer and sell shares of our common stock, $0.0001 par value per share, from time to

Keros Therapeutics to Host a Corporate Update Conference Call and Webcast

Exhibit 99.1 Keros Therapeutics to Host a Corporate Update Conference Call and Webcast LEXINGTON, Mass., June 4, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel treatments to treat a wide range of patients with disorders that are linked to dysfunct

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 4, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission F

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 3, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission F

Keros Therapeutics to Present at Goldman Sachs 45th Annual Global Healthcare Conference

Exhibit 99.1 Keros Therapeutics to Present at Goldman Sachs 45th Annual Global Healthcare Conference LEXINGTON, Mass., June 3, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel treatments to treat a wide range of patients with disorders that are linked to dysfunc

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 30, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission F

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 23, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission F

Keros Therapeutics Appoints Jean-Jacques Bienaimé to its Board of Directors

Exhibit 99.1 Keros Therapeutics Appoints Jean-Jacques Bienaimé to its Board of Directors LEXINGTON, Mass., May 28, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional signali

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 8, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission Fi

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39264 KEROS THE

KEROS THERAPEUTICS, INC. Condensed Consolidated Statements of Operations (In thousands, except share and per share data) THREE MONTHS ENDED MARCH 31, 2024 2023 REVENUE: Service and other revenue 83 — Total revenue 83 — OPERATING EXPENSES: Research an

Exhibit 99.1 Keros Therapeutics Reports Recent Business Highlights and First Quarter 2024 Financial Results LEXINGTON, Mass., May 8, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dys

As filed with the Securities and Exchange Commission on May 3, 2024

As filed with the Securities and Exchange Commission on May 3, 2024 Registration No.

Form of Preferred Stock Warrant Agreement and Warrant Certificate

Exhibit 4.8 KEROS THERAPEUTICS, INC. AND , AS WARRANT AGENT FORM OF PREFERRED STOCK WARRANT AGREEMENT DATED AS OF KEROS THERAPEUTICS, INC. FORM OF PREFERRED STOCK WARRANT AGREEMENT THIS PREFERRED STOCK WARRANT AGREEMENT (this “Agreement”), dated as of [l], between KEROS THERAPEUTICS, INC., a Delaware corporation (the “Company”), and [l], a [corporation] [national banking association] organized and

Form of Indenture

Exhibit 4.4 Keros Therapeutics, Inc., Issuer AND [TRUSTEE], Trustee INDENTURE Dated as of [l], 20 Debt Securities TABLE OF CONTENTS PAGE ARTICLE 1 DEFINITIONS 1 Section 1.01 Definitions of Terms 1 ARTICLE 2 ISSUE, DESCRIPTION, TERMS, EXECUTION, REGISTRATION AND EXCHANGE OF SECURITIES 5 Section 2.01 Designation and Terms of Securities 5 Section 2.02 Form of Securities and Trustee’s Certificate 7 Se

Form of Debt Securities Warrant Agreement and Warrant Certificate

Exhibit 4.9 KEROS THERAPEUTICS, INC. AND , AS WARRANT AGENT FORM OF DEBT SECURITIES WARRANT AGREEMENT DATED AS OF KEROS THERAPEUTICS, INC. FORM OF DEBT SECURITIES WARRANT AGREEMENT THIS DEBT SECURITIES WARRANT AGREEMENT (this “Agreement”), dated as of [●], between KEROS THERAPEUTICS, INC., a Delaware corporation (the “Company”), and [●], a [corporation] [national banking association] organized and

iling Fee Table.

Exhibit 107 Calculation of Registration Fee Form S-3 (Form Type) Keros Therapeutics, Inc.

Form of Common Stock Warrant Agreement and Warrant Certificate

Exhibit 4.7 KEROS THERAPEUTICS, INC. AND , AS WARRANT AGENT FORM OF COMMON STOCK WARRANT AGREEMENT DATED AS OF KEROS THERAPEUTICS, INC. FORM OF COMMON STOCK WARRANT AGREEMENT THIS COMMON STOCK WARRANT AGREEMENT (this “Agreement”), dated as of [●], between KEROS THERAPEUTICS, INC., a Delaware corporation (the “Company”), and [●], a [corporation] [national banking association] organized and existing

ARS

NASDAQ: KROS 2023 Annual ReportUNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.       )

TABLE OF CONTENTS SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.

Keros Therapeutics Announces U.S. FDA Fast Track Designation for KER-050 in Lower-Risk Myelodysplastic Syndromes

Exhibit 99.1 Keros Therapeutics Announces U.S. FDA Fast Track Designation for KER-050 in Lower-Risk Myelodysplastic Syndromes LEXINGTON, Mass., March 14, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 14, 2024 Keros Therapeutics

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 14, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 6, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

March 2024 Corporate Presentation Corporate Presentation Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of

March 2024 Corporate Presentation Corporate Presentation Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 29, 2024 Keros Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 29, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commiss

Keros Therapeutics to Present at Leerink Partners 2024 Global Biopharma Conference

Exhibit 99.1 Keros Therapeutics to Present at Leerink Partners 2024 Global Biopharma Conference LEXINGTON, Mass., March 5, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional signaling of the

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 5, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

Filing fee table.

Exhibit 107 Calculation of Filing Fee Tables Form S-8 Keros Therapeutics, Inc. (Exact Name of Registrant as Specified in its Charter) Security Type Security Class Title Fee Calculation Rule Amount Registered(1) Proposed Maximum Offering Price Per Share Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee(6) Equity 2020 Equity Incentive Plan, Common Stock, $0.0001 par value per shar

As filed with the Securities and Exchange Commission on February 28, 2024

As filed with the Securities and Exchange Commission on February 28, 2024 Registration No.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 28, 2024 Keros Therapeut

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 28, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commiss

KEROS THERAPEUTICS, INC. Consolidated Statements of Operations (In thousands, except share and per share data) THREE MONTHS ENDED DECEMBER 31, YEAR ENDED DECEMBER 31, 2023 2022 2023 2022 REVENUE: Service and other revenue 143 — 151 — Total revenue 14

Exhibit 99.1 Keros Therapeutics Reports Recent Business Highlights and Fourth Quarter and Full Year 2023 Financial Results LEXINGTON, Mass., February 28, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders t

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39264 KEROS THERAPEU

Incentive Compensation Recoupment Policy.

Exhibit 97 KEROS THERAPEUTICS, INC. INCENTIVE COMPENSATION RECOUPMENT POLICY 1. Introduction The Board of Directors (the “Board”) of Keros Therapeutics, Inc., a Delaware corporation (the “Company”), has determined that it is in the best interests of the Company and its stockholders to adopt this Incentive Compensation Recoupment Policy (this “Policy”) providing for the Company’s recoupment of Reco

Subsidiaries of Keros Therapeutics, Inc.

Exhibit 21.1 Subsidiaries of Keros Therapeutics, Inc. Name of Subsidiary Jurisdiction of Organization Keros Therapeutics Australia, Pty Ltd Australia Keros Security Corporation Massachusetts

Exhibit 4.3

Exhibit 4.3 DESCRIPTION OF KEROS THERAPEUTICS, INC. COMMON STOCK The following description of the common stock of Keros Therapeutics, Inc., or the Company, is a summary and does not purport to be complete. This summary is qualified in its entirety by reference to the provisions of the Delaware General Corporation Law, or the DGCL, and the complete text of the Company’s amended and restated certifi

Amendment No. 4 dated as of April 12, 2023, to License Agreement by and between the registrant and Hansoh (Shanghai) Healthtech Co., Ltd.

Exhibit 10.12 CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY [***], HAS BEEN OMITTED BECAUSE KEROS THERAPEUTICS, INC. HAS DETERMINED THE INFORMATION (I) IS NOT MATERIAL AND (II) WOULD LIKELY CAUSE COMPETITIVE HARM TO KEROS THERAPEUTICS, INC. IF PUBLICLY DISCLOSED. AMENDMENT NO. 4 TO LICENSE AGREEMENT This AMENDMENT NO. 4 (this “Amendment”) is entered into as of April 12, 20

KROS / Keros Therapeutics, Inc. / ALKEON CAPITAL MANAGEMENT LLC Passive Investment

SC 13G/A 1 kros13ga2024.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1) Keros Therapeutics, Inc. (Name of Issuer) Common Stock, par value $0.0001 per share (Title of Class of Securities) 492327101 (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statement) Check the app

KROS / Keros Therapeutics, Inc. / FMR LLC Passive Investment

SCHEDULE 13G Amendment No.4 KEROS THERAPEUTICS INC COMMON STOCK Cusip #492327101 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: [x] Rule 13d-1(b) [ ] Rule 13d-1(c) [ ] Rule 13d-1(d) Cusip #492327101 Item 1: Reporting Person - FMR LLC Item 2: (a) [ ] (b) [ ] Item 4: Delaware Item 5: 3,873,924 Item 6: 0 Item 7: 3,874,204 Item 8: 0 Item 9: 3,874,204 Item 11:

KROS / Keros Therapeutics, Inc. / BlackRock Inc. Passive Investment

us4923271013012624.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 3) Keros Therapeutics, Inc. - (Name of Issuer) Common Stock - (Title of Class of Securities) 492327101 - (CUSIP Number) December 31, 2023 - (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursu

Keros Therapeutics Announces Closing of Upsized Public Offering of Common Stock

Exhibit 99.1 Keros Therapeutics Announces Closing of Upsized Public Offering of Common Stock LEXINGTON, Mass., Jan. 9, 2024 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or “we”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional signaling of

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 9, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissio

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 3, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissio

Calculation of Filing Fee Tables (Form Type) Keros Therapeutics, Inc. (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered and Carry Forward Securities

Exhibit 107 Calculation of Filing Fee Tables 424(b)(5) (Form Type) Keros Therapeutics, Inc.

, 2024, by and among the Company, Goldman Sachs & Co. LLC, Leerink Partners LLC, Piper Sandler & Co. and Truist Securities, Inc

Exhibit 1.1 Execution Version 3,500,000 Shares Keros Therapeutics, Inc. Common Stock UNDERWRITING AGREEMENT January 3, 2024 GOLDMAN SACHS & CO. LLC LEERINK PARTNERS LLC PIPER SANDLER & CO. TRUIST SECURITIES, INC. As Representatives of the several Underwriters c/o GOLDMAN SACHS & CO. LLC 200 West Street New York, New York 10282 c/o LEERINK PARTNERS LLC 53 State Street, 40th Floor Boston, Massachuse

3,500,000 Shares Common Stock

Filed Pursuant to Rule 424(b)(5) Registration No. 333-255724 Prospectus Supplement (To Prospectus dated May 3, 2021) 3,500,000 Shares Common Stock We are offering 3,500,000 shares of our common stock to be sold in the offering. Our common stock is listed on The Nasdaq Global Market under the symbol “KROS.” On January 3, 2024, the last reported sale price of our common stock as reported on The Nasd

January 2024 Corporate Presentation Corporate Presentation 2 Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act

January 2024 Corporate Presentation Corporate Presentation 2 Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended.

Regulation FD Disclosure, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 3, 2024 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissio

Subject to Completion, dated January 3, 2024

Filed Pursuant to Rule 424(b)(5) Registration No. 333-255724 The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell the securities and are not soliciting an offer to buy the securities in any jurisdiction where the offer or sale is not permitted. Subject to Complet

Keros Therapeutics to Develop KER-065 for the Treatment of Obesity

Exhibit 99.2 Keros Therapeutics to Develop KER-065 for the Treatment of Obesity •Keros commenced a randomized, double-blind, placebo-controlled, two-part Phase 1 clinical trial to evaluate single and multiple ascending doses of KER-065 in healthy volunteers •Keros expects to report initial data from this Phase 1 clinical trial in the first quarter of 2025 •Preclinical data showed potential proof-o

JOINT FILING AGREEMENT

EX-99.1 2 ss2818988ex9901.htm JOINT FILING AGREEMENT Exhibit 1 JOINT FILING AGREEMENT The undersigned hereby agree that Amendment No. 3 to the Statement on Schedule 13D, dated December 11, 2023, with respect to the common stock, par value $0.0001 per share, of Keros Therapeutics, Inc. is filed on behalf of each of us pursuant to and in accordance with the provisions of Rule 13d-1(k) under the Secu

KROS / Keros Therapeutics Inc / ORBIMED ADVISORS LLC - AMENDMENT NO. 3 Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 3)* Keros Therapeutics, Inc. (Name of Issuer) COMMON STOCK (Title of Class of Securities) 492327101 (CUSIP Number) OrbiMed Advisors LLC OrbiMed Capital GP VII LLC OrbiMed Genesis GP LLC OrbiMed Capital LLC 601 Lexington Avenue, 54th Floor New York, NY 10022

Hematology Franchise: Update at 65th Annual Congress of the American Society of Hematology December 2023 Hematology Franchise Update 2 Statements contained in this presentation regarding matters that are not historical facts are “forward-looking stat

Hematology Franchise: Update at 65th Annual Congress of the American Society of Hematology December 2023 Hematology Franchise Update 2 Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended.

Keros Therapeutics Presents Clinical Data from its KER-050 Program at the 65th American Society of Hematology Annual Meeting and Exposition

Exhibit 99.1 Keros Therapeutics Presents Clinical Data from its KER-050 Program at the 65th American Society of Hematology Annual Meeting and Exposition •KER-050 (elritercept) achieved durable transfusion independence in lower-risk MDS, including in patients with high transfusion burden •Durable clinical responses were associated with improvements in patient-reported measures of fatigue •Biomarker

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 11, 2023 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commiss

Keros Therapeutics to Present at Upcoming Healthcare Conferences

Exhibit 99.1 Keros Therapeutics to Present at Upcoming Healthcare Conferences LEXINGTON, Mass., November 7, 2023 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional signaling of the transforming g

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 7, 2023 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissi

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 6, 2023 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissi

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 6, 2023 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissi

November 2023 Corporate Presentation Corporate Presentation 2 Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Ac

November 2023 Corporate Presentation Corporate Presentation 2 Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39264 KEROS

KEROS THERAPEUTICS, INC. Condensed Consolidated Statements of Operations (In thousands, except share and per share data) THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, 2023 2022 2023 2022 REVENUE: Service revenue $ 8 $ — $ 8 $ — Tot

Exhibit 99.1 Keros Therapeutics Reports Recent Business Highlights and Third Quarter 2023 Financial Results November 6, 2023 at 8:00 AM EST LEXINGTON, Mass., November 6, 2023 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 4, 2023 Keros Therapeutic

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 4, 2023 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commissio

Keros Therapeutics Presents Preclinical Data from its KER-065 Program at the 28th International Annual Congress of the World Muscle Society

Exhibit 99.1 Keros Therapeutics Presents Preclinical Data from its KER-065 Program at the 28th International Annual Congress of the World Muscle Society LEXINGTON, Mass., October 4, 2023 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 5, 2023 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commiss

Keros Therapeutics to Present at Upcoming Healthcare Conferences

Exhibit 99.1 Keros Therapeutics to Present at Upcoming Healthcare Conferences LEXINGTON, Mass., September 5, 2023 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional signaling of the transforming

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39264 KEROS THER

Regulation FD Disclosure, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 7, 2023 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

August 2023 Corporate Presentation Corporate Presentation 2 Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act

exhibit991 August 2023 Corporate Presentation Corporate Presentation 2 Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended.

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 7, 2023 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

KEROS THERAPEUTICS, INC. Condensed Consolidated Statements of Operations (In thousands, except share and per share data) THREE MONTHS ENDED JUNE 30, SIX MONTHS ENDED JUNE 30, 2023 2022 2023 2022 OPERATING EXPENSES: Research and development (32,534) (

Exhibit 99.1 Keros Therapeutics Reports Recent Business Highlights and Second Quarter 2023 Financial Results August 7, 2023 at 8:00 AM EST LEXINGTON, Mass., August 07, 2023 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients wi

August 8, 2023 KER-012 Update KER-012 Update 2 Disclaimer Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of

exhibit992 August 8, 2023 KER-012 Update KER-012 Update 2 Disclaimer Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 24, 2023 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 24, 2023 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission

Keros Therapeutics to Host Conference Call and Webcast to Provide an Overview of TROPOS, the KER-012 Phase 2 Clinical Trial in Patients with Pulmonary Arterial Hypertension

Exhibit 99.1 Keros Therapeutics to Host Conference Call and Webcast to Provide an Overview of TROPOS, the KER-012 Phase 2 Clinical Trial in Patients with Pulmonary Arterial Hypertension •Keros Therapeutics announces U.S. Food and Drug Administration (“FDA”) has cleared its investigational new drug application to conduct a Phase 2 clinical trial of KER-012 in combination with background therapy in

Keros Therapeutics Presents Clinical Trial and Preclinical Study Results from its KER-050 Program and Preclinical Data from its ALK2 Inhibitor Program at the 28th Annual Congress of the European Hematology Association

Exhibit 99.1 Keros Therapeutics Presents Clinical Trial and Preclinical Study Results from its KER-050 Program and Preclinical Data from its ALK2 Inhibitor Program at the 28th Annual Congress of the European Hematology Association •Keros Therapeutics will be hosting a conference call and webcast today, June 9, 2023, at 8:00 a.m. Eastern time, to provide an update on its hematology franchise. Lexin

June 9, 2023 Hematology Franchise: Program Updates and Summary of Data Presented at 28th Annual Congress of the European Hematology Association Disclaimer Statements contained in this presentation regarding matters that are not historical facts are “

eha2023kerosinvestorcal June 9, 2023 Hematology Franchise: Program Updates and Summary of Data Presented at 28th Annual Congress of the European Hematology Association Disclaimer Statements contained in this presentation regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 9, 2023 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 9, 2023 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 7, 2023 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 7, 2023 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission F

Keros Therapeutics to Present at Goldman Sach’s 44

Exhibit 99.1 Keros Therapeutics to Present at Goldman Sach’s 44th Annual Global Healthcare Conference LEXINGTON, Mass., June 7, 2023 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel treatments for patients suffering from hematological, pulmonary and cardiovascular di

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 6, 2023 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 6, 2023 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission F

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 22, 2023 Keros Therapeutics,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 22, 2023 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission F

Keros Therapeutics Presents Preclinical and Clinical Data from its KER-012 Program at the American Thoracic Society International Conference

Exhibit 99.1 Keros Therapeutics Presents Preclinical and Clinical Data from its KER-012 Program at the American Thoracic Society International Conference LEXINGTON, Mass., May 22, 2023 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel treatments for patients suffering

Amended and Restated Non-Employee Director Compensation Policy

Exhibit 10.2 Keros Therapeutics, Inc. Amended and Restated Non-Employee Director Compensation Policy Each member of the Board of Directors (the “Board”) who is not also serving as an employee of or consultant to Keros Therapeutics, Inc. (the “Company”) or any of its subsidiaries (each such member, an “Eligible Director”) will receive the compensation described in this Amended and Restated Non-Empl

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-39264 KEROS THE

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 4, 2023 Keros Therapeutics, I

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 4, 2023 Keros Therapeutics, Inc. (Exact name of registrant as specified in its charter) Delaware 001-39264 81-1173868 (state or other jurisdiction of incorporation) (Commission Fi

KEROS THERAPEUTICS, INC. Condensed Consolidated Statements of Operations (In thousands, except share and per share data) THREE MONTHS ENDED MARCH 31, 2023 2022 REVENUE: License revenue $ — $ — Total revenue — — OPERATING EXPENSES: Research and develo

EX-99.1 2 exhibit991q12023.htm EX-99.1 Exhibit 99.1 Keros Therapeutics Reports Recent Business Highlights and First Quarter 2023 Financial Results LEXINGTON, Mass., May 4, 2023 (GLOBE NEWSWIRE) - Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of novel treatments for patients

egistrant and Revolution Labs Owner, LLC, dated January 6, 2023.

Exhibit 10.1 FIRST AMENDMENT TO LEASE This FIRST AMENDMENT TO LEASE (this “Amendment”) is made as of this 6th day of January, 2023 (the “Execution Date”) by and between REVOLUTION LABS OWNER, LLC, a Delaware limited liability company (“Landlord”), and KEROS THERAPEUTICS, INC., a Delaware corporation (“Tenant”). WITNESSETH: Reference is hereby made to the following facts: A. Landlord and Tenant are

ARS

2022 ANNUAL REPORT NASDAQ: KROS Corporate Headquarters 1050 Waltham Street, Suite 302 Lexington, MA 02421 www.