Climb Bio, Inc. — Director's Dealing 2025

Jun 5, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Climb Bio, Inc. (CLYM)
CIK: 0001768446
Period of Report: 2025-06-04

Reporting Person: RA CAPITAL MANAGEMENT, L.P. (N/A)
Reporting Person: RA Capital Healthcare Fund LP (Director, 10% Owner)
Reporting Person: RA Capital Nexus Fund, L.P. (Director)
Reporting Person: RA Capital Nexus Fund II, L.P. (Director)
Reporting Person: RA Capital Nexus Fund III, L.P. (Director)
Reporting Person: Kolchinsky Peter (Director, 10% Owner)
Reporting Person: Shah Rajeev M. (Director, 10% Owner)

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2025-06-04	Stock Option (Right to Buy)	$1.29	A	40000	Acquired	2035-06-03	Common Stock (40000)	Indirect

Footnotes

F1: The shares subject to the option will vest on the earlier of June 4, 2026 or the day immediately prior to the next annual meeting of stockholders, subject to Dr. Andrew Levin's continuous service through such date.

F2: RA Capital Management, L.P. (the "Adviser") is the investment manager for RA Capital Healthcare Fund, L.P. (the "Fund"), RA Capital Nexus Fund, L.P. (the "Nexus Fund"), RA Capital Nexus Fund II, L.P. (the "Nexus Fund II"), RA Capital Nexus Fund III, L.P. (the "Nexus Fund III"),and a separately managed account (the "Account"). The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. Each of the Adviser, the Adviser GP, the Fund, the Nexus Fund, the Nexus Fund II, the Nexus Fund III, Dr. Kolchinsky and Mr. Shah disclaims beneficial ownership of any of the reported securities, except to the extent of its or his respective pecuniary interest therein.

F3: Dr. Andrew Levin is a Partner and Managing Director of the Adviser who serves on the Issuer's board of directors. Under Dr. Levin's arrangement with the Adviser, Dr. Levin holds the option for the benefit of the Fund, the Nexus Fund, the Nexus Fund II, the Nexus Fund III, and the Account. Dr. Levin is obligated to turn over to the Adviser any net cash or stock received upon exercise of the option, which will offset advisory fees owed by the Fund, the Nexus Fund, the Nexus Fund II, the Nexus Fund III, and the Account to the Adviser. The Reporting Persons therefore disclaim beneficial ownership of the option and underlying common stock.