RA CAPITAL MANAGEMENT, L.P. - 29 Apr 2026 Form 4 Insider Report for Climb Bio, Inc. (CLYM)

Reporting relationship
Director, 10%+ Owner
Issuer ticker
CLYM
Reported as of
29 Apr 2026
Net transaction value
$0
Source evidence Original filing metadata and source links for verification. 5 source fields
SEC form
4
Accepted by SEC
29 Apr 2026, 18:46:09 UTC
Prior SEC filing
28 Apr 2026
Next SEC filing
30 Apr 2026
Source filing
View source filing
Reporting owner 1 detail
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 29 Apr 2026.

Key facts

  • This page summarizes RA CAPITAL MANAGEMENT, L.P.'s Form 4 filing for Climb Bio, Inc. (CLYM).
  • 1 reported transaction and 7 derivative rows are listed below.
  • Accepted by SEC: 29 Apr 2026, 18:46.

Change

  • Previous filing in this sequence was filed on 28 Apr 2026.
  • Current net transaction value: $0.

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
29 Apr 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
29 Apr 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
29 Apr 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
29 Apr 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
29 Apr 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
29 Apr 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
29 Apr 2026

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

CLYM transaction Derivative

Pre-Funded Warrants (Right to Buy)

Award

Transaction value
Shares
+2,106,000
Change %
+10%
Price
$9.50*
Shares after
22,546,000
Date
29 Apr 2026
Ownership
See footnotes
Underlying class
Common Stock
Underlying amount
2,106,000
Exercise price
$0.000100
Footnotes
F1, F2, F3
CLYM transaction Derivative

Pre-Funded Warrants (Right to Buy)

Award

Transaction value
Shares
+2,106,000
Change %
+10%
Price
$9.50*
Shares after
22,546,000
Date
29 Apr 2026
Ownership
See footnotes
Underlying class
Common Stock
Underlying amount
2,106,000
Exercise price
$0.000100
Footnotes
F1, F2, F3
CLYM transaction Derivative

Pre-Funded Warrants (Right to Buy)

Award

Transaction value
Shares
+2,106,000
Change %
+10%
Price
$9.50*
Shares after
22,546,000
Date
29 Apr 2026
Ownership
See footnotes
Underlying class
Common Stock
Underlying amount
2,106,000
Exercise price
$0.000100
Footnotes
F1, F2, F3
CLYM transaction Derivative

Pre-Funded Warrants (Right to Buy)

Award

Transaction value
Shares
+2,106,000
Change %
+10%
Price
$9.50*
Shares after
22,546,000
Date
29 Apr 2026
Ownership
See footnotes
Underlying class
Common Stock
Underlying amount
2,106,000
Exercise price
$0.000100
Footnotes
F1, F2, F3
CLYM transaction Derivative

Pre-Funded Warrants (Right to Buy)

Award

Transaction value
Shares
+2,106,000
Change %
+10%
Price
$9.50*
Shares after
22,546,000
Date
29 Apr 2026
Ownership
See footnotes
Underlying class
Common Stock
Underlying amount
2,106,000
Exercise price
$0.000100
Footnotes
F1, F2, F3
CLYM transaction Derivative

Pre-Funded Warrants (Right to Buy)

Award

Transaction value
Shares
+2,106,000
Change %
+10%
Price
$9.50*
Shares after
22,546,000
Date
29 Apr 2026
Ownership
See footnotes
Underlying class
Common Stock
Underlying amount
2,106,000
Exercise price
$0.000100
Footnotes
F1, F2, F3
CLYM transaction Derivative

Pre-Funded Warrants (Right to Buy)

Award

Transaction value
Shares
+2,106,000
Change %
+10%
Price
$9.50*
Shares after
22,546,000
Date
29 Apr 2026
Ownership
See footnotes
Underlying class
Common Stock
Underlying amount
2,106,000
Exercise price
$0.000100
Footnotes
F1, F2, F3
* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 3 footnotes

Footnote F1

The Pre-Funded Warrants have no expiration date and are exercisable immediately. Notwithstanding the foregoing, the Reporting Persons shall not be entitled to exercise the Pre-Funded Warrant if it would cause the aggregate number of shares of Common Stock beneficially owned by the Reporting Persons, their affiliates and any persons who are members of a Section 13(d) group with the Reporting Persons or their affiliates to exceed 33.0% of the total number of issued and outstanding shares of Common Stock of the Issuer following such exercise.

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.

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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