tm2528628-1_sctoi_DIV_05-exha1c - none

Exhibit (a)(1)(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, UNLESS THE OFFER IS EXTENDED (SUCH DATE AND TIME, AS THEY MAY BE EXTENDED, THE “EXPIRATION TIME”)
OR TERMINATED.

As set forth in Section 3 of the Offer to Purchase (as defined below) this form must be used to accept the Offer (as defined below) if (1) certificates representing your shares of common stock, $0.0001 par value per share, of Keros Therapeutics, Inc., a Delaware corporation, are not immediately available or cannot be delivered to the Depositary prior to the Expiration Time, (2) the procedures for book-entry transfer cannot be completed on a timely basis or (3) time will not permit all required documents to reach the Depositary at or prior to the Expiration Time. This form may be delivered by overnight courier or by mail to the Depositary. See Section 3 of the Offer to Purchase. Capitalized terms used herein without definition have the meanings set forth in the Offer to Purchase.

The Depositary for the Offer is:
Computershare Trust Company, N.A.

By First Class, Registered or Certified Mail: Computershare Trust Company, N.A.
c/o Voluntary Corporate Actions
PO Box 43011
Providence, RI 02940-3011

By Express or Overnight Delivery:
Computershare Trust Company, N.A.
c/o Voluntary Corporate Actions
150 Royall Street, Suite V
Canton, MA 02021

DELIVERY OF THIS NOTICE OF GUARANTEED DELIVERY TO AN ADDRESS OTHER THAN AS SET FORTH ABOVE WILL NOT CONSTITUTE A VALID DELIVERY.

This Notice is not to be used to guarantee signatures. If a signature on a Letter of Transmittal is required to be guaranteed by an eligible institution under the instructions in the Letter of Transmittal, the signature guarantee must appear in the applicable space provided in the signature box on the Letter of Transmittal.

Ladies and Gentlemen:

The undersigned hereby tenders to Keros Therapeutics, Inc., a Delaware corporation (the “Company”), on the terms and subject to the conditions set forth in the Offer to Purchase dated October 20, 2025 (the “Offer to Purchase”), and the related Letter of Transmittal (which, together with any amendments or supplements thereto, collectively constitute the “Offer”), receipt of which is hereby acknowledged, the number of shares set forth below, all pursuant to the guaranteed delivery procedures set forth in Section 3 of the Offer to Purchase.

		Number of shares to be tendered: shares*
		* Unless otherwise indicated, it will be assumed that all shares held by the undersigned are to be tendered.

		CONDITIONAL TENDER (See Instruction 14 of the Letter of Transmittal)
		A tendering stockholder may condition the tender of shares upon the Company purchasing a specified minimum number of the shares tendered, all as described in Section 6 of the Offer to Purchase. Unless at least the minimum number of shares you indicate below is purchased by the Company pursuant to the terms of the Offer, none of the shares tendered by you will be purchased. It is the tendering stockholder’s responsibility to calculate the minimum number of shares that must be purchased if any are purchased, and each stockholder is urged to consult his, her or its own tax advisor before completing this section. Unless this box has been checked and a minimum specified, your tender will be deemed unconditional.
		☐ The minimum number of shares that must be purchased from me, if any are purchased from me, is: shares.
		If, because of proration, the minimum number of shares designated will not be purchased, the Company may accept conditional tenders by random lot, if necessary. However, to be eligible for purchase by random lot, the tendering stockholder must have tendered all of his, her or its shares and checked this box:
		☐ The tendered shares represent all shares held by the undersigned.

		Certificate Nos. (if available):
		Name(s) of Record Holder(s):
		(Please Type or Print)
		Address(es):
		Zip Code:
		Daytime Area Code and Telephone Number:
		Signature(s):
		Dated: , 2025
		If shares will be tendered by book-entry transfer, check this box ☐ and provide the following information:
		Name of Tendering Institution:
		Account Number at Book-Entry Transfer Facility:
		THE GUARANTEE SET FORTH BELOW MUST BE COMPLETED.

		GUARANTEE (Not To Be Used For Signature Guarantee)
		The undersigned, a firm that is a member in good standing of a recognized Medallion Program approved by the Securities Transfer Association, Inc., including the Securities Transfer Agents Medallion Program, the New York Stock Exchange, Inc. Medallion Signature Program or the Stock Exchange Medallion Program, or is otherwise an “eligible guarantor institution,” as that term is defined in Rule 17Ad-15 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), hereby guarantees (1) that the above named person(s) “own (s)” the shares tendered hereby within the meaning of Rule 14e-4 under the Exchange Act, (2) that such tender of shares complies with Rule 14e-4 under the Exchange Act and (3) to deliver to the Depositary either the certificates representing the shares tendered hereby, in proper form for transfer, or a book-entry confirmation (as defined in the Offer to Purchase) with respect to such shares, in any such case together with a properly completed and duly executed Letter of Transmittal, with any required signature guarantees, or an agent’s message (as defined in the Offer to Purchase) in the case of a book-entry delivery, and any other required documents, within one trading day (as defined in the Offer to Purchase) after the Expiration Time. Participants tendering their shares should notify the Depositary prior to covering through the submission of a physical security directly to the Depositary based on a guaranteed delivery that was submitted via DTC’s PTOP platform.
		The eligible institution that completes this form must communicate the guarantee to the Depositary and must deliver the Letter of Transmittal and certificates for shares to the Depositary within the time period shown herein. Failure to do so could result in financial loss to such eligible institution.
		Name of Firm:
		Authorized Signature:
		Name:
		(Please Type or Print)
		Title:
		Address:
		Zip Code:
		Area Code and Telephone Number:
		Dated: , 2025

Note: Do not send certificates for shares with this Notice.
Certificates for shares should be sent with your Letter of Transmittal.