RA CAPITAL MANAGEMENT, L.P. - 05 Jan 2026 Form 4 Insider Report for Climb Bio, Inc. (CLYM)

Reporting relationship: Director, 10%+ Owner
Issuer ticker: CLYM
Reported as of: 05 Jan 2026
Net transaction value: +$24,888
SEC form: 4
Accepted by SEC: 07 Jan 2026, 16:55:47 UTC
Prior SEC filing: 19 Dec 2025
Next SEC filing: 09 Jan 2026
Source filing: View source filing
Reporting owner signature: /s/ Peter Kolchinsky, Manager of RA Capital Management, L.P.

Key filing fact

RA CAPITAL MANAGEMENT, L.P. filed Form 4 for Climb Bio, Inc. (CLYM) on 07 Jan 2026.

Key facts

This page summarizes RA CAPITAL MANAGEMENT, L.P.'s Form 4 filing for Climb Bio, Inc. (CLYM).
1 reported transaction and 0 derivative rows are listed below.
Accepted by SEC: 07 Jan 2026, 16:55.

Change

Previous filing in this sequence was filed on 19 Dec 2025.
Current net transaction value: +$24,888.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (7)

CIK 0001346824 Primary reporting owner

RA CAPITAL MANAGEMENT, L.P.

Relationship: Director, 10%+ Owner
Address: 200 BERKELEY STREET, 18TH FLOOR, BOSTON
Signature: /s/ Peter Kolchinsky, Manager of RA Capital Management, L.P.
Signature date: 07 Jan 2026

CIK 0001315082

RA Capital Healthcare Fund LP

Relationship: Director, 10%+ Owner
Address: 200 BERKELEY STREET, 18TH FLOOR, BOSTON
Signature: /s/ Peter Kolchinsky, Manager of RA Capital Healthcare Fund GP, LLC the General Partner of RA Capital Healthcare Fund, L.P.
Signature date: 07 Jan 2026

CIK 0001780117

RA Capital Nexus Fund, L.P.

Relationship: Director
Address: 200 BERKELEY STREET, 18TH FLOOR, BOSTON
Signature: /s/ Peter Kolchinsky, Manager of RA Capital Nexus Fund GP, LLC, the General Partner of RA Capital Nexus Fund, L.P.
Signature date: 07 Jan 2026

CIK 0001825376

RA Capital Nexus Fund II, L.P.

Relationship: Director
Address: 200 BERKELEY STREET, 18TH FLOOR, BOSTON
Signature: /s/ Peter Kolchinsky, Manager of RA Capital Nexus Fund II GP, LLC, the General Partner of RA Capital Nexus Fund II, L.P.
Signature date: 07 Jan 2026

CIK 0001883840

RA Capital Nexus Fund III, L.P.

Relationship: Director, 10%+ Owner
Address: 200 BERKELEY STREET, 18TH FLOOR, BOSTON
Signature: /s/ Peter Kolchinsky, Manager of RA Capital Nexus Fund III GP, LLC, the General Partner of RA Capital Nexus Fund III, L.P.
Signature date: 07 Jan 2026

CIK 0001384859

Kolchinsky Peter

Relationship: Director, 10%+ Owner
Address: C/O RA CAPITAL MANAGEMENT, L.P., 200 BERKELEY STREET, 18TH FLOOR, BOSTON
Signature: /s/ Peter Kolchinsky, individually
Signature date: 07 Jan 2026

CIK 0001619841

Shah Rajeev M.

Relationship: Director, 10%+ Owner
Address: C/O RA CAPITAL MANAGEMENT, L.P., 200 BERKELEY STREET, 18TH FLOOR, BOSTON
Signature: /s/ Rajeev Shah, individually
Signature date: 07 Jan 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

CLYM transaction

Common Stock

Purchase

Transaction value: $24,888
Shares: +7,111
Change %: +0.21%
Price: $3.50
Shares after: 3,403,429
Date: 05 Jan 2026
Ownership: See footnotes
Footnotes: F1, F2, F3

CLYM holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 2,479,872
Date: 05 Jan 2026
Ownership: See footnotes
Footnotes: F3, F4

CLYM holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 1,226,497
Date: 05 Jan 2026
Ownership: See footnotes
Footnotes: F3, F5

CLYM holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 483,679
Date: 05 Jan 2026
Ownership: See footnotes
Footnotes: F3, F6

CLYM holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 2,866,375
Date: 05 Jan 2026
Ownership: See footnotes
Footnotes: F3, F7

CLYM holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 841,087
Date: 05 Jan 2026
Ownership: See footnotes
Footnotes: F3, F8

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 8 footnotes

Footnote F1

The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $3.495 to $3.50 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

Footnote F2

These securities are held directly by RA Capital Healthcare Fund, L.P. (the "Fund").

Footnote F3

RA Capital Management, L.P. (the "Adviser") is the investment manager for the Fund, RA Capital Nexus Fund, L.P. (the "Nexus Fund"), RA Capital Nexus II Fund, L.P. (the "Nexus Fund II"), RA Capital Nexus III Fund, 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. The Fund and the Nexus Fund III collectively own approximately 75% of the outstanding equity interests of Sera Medicines, LLC ("Sera"). Accordingly, each of the Fund, the Nexus Fund III and the Adviser may be deemed to beneficially own the securities held by Sera. The Adviser, the Adviser GP, the Fund, the Nexus Fund, the Nexus Fund II, the Nexus Fund III, Dr. Kolchinsky and Mr. Shah disclaim beneficial ownership of the reported securities, except to the extent of their respective pecuniary interest therein.

Footnote F4

These securities are held directly by Sera.

Footnote F5

These securities are held directly by the Nexus Fund.

Footnote F6

These securities are held directly by the Nexus Fund II.

Footnote F7

These securities are held directly by Nexus Fund III.

Footnote F8

These securities are held directly by the Account.

SEC remarks

Dr. Andrew Levin, a Partner and Managing Director of the Adviser, serves on the Issuer's board of directors.

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