Susan Altschuller - 01 Oct 2025 Form 4 Insider Report for Climb Bio, Inc. (CLYM)

Role: Chief Financial Officer
Signature: /s/ Chandra Adams, as Attorney-in-Fact
Issuer symbol: CLYM
Transactions as of: 01 Oct 2025
Net transactions value: $0
Form type: 4
Filing time: 01 Oct 2025, 17:52:50 UTC
Previous filing: 15 Aug 2024
Next filing: 08 Jan 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
ALTSCHULLER Susan	Chief Financial Officer	C/O CLIMB BIO, INC., 20 WILLIAM STREET, SUITE 145, WELLESLEY HILLS	/s/ Chandra Adams, as Attorney-in-Fact	01 Oct 2025	0001817988

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	CLYM	Stock Option (Right to Buy)	Award	$0	+600,000		$0.000000	600,000	01 Oct 2025	Common Stock	600,000	$1.97	Direct	F1

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	This option was granted on October 1, 2025 (the "Grant Date"). The shares underlying the option are scheduled to vest with respect to 25% of the shares on the first anniversary of the Grant Date, and the remainder are scheduled to vest in 36 equal monthly installments through October 1, 2029, subject to the Reporting Person's continued service.