Ansbert Gadicke - 18 Nov 2025 Form 4 Insider Report for Werewolf Therapeutics, Inc. (HOWL)

Reporting relationship: 10%+ Owner
Issuer ticker: HOWL
Reported as of: 18 Nov 2025
Net transaction value: -$147,913
SEC form: 4
Accepted by SEC: 20 Nov 2025, 17:50:30 UTC
Prior SEC filing: 17 Nov 2025
Next SEC filing: 25 Nov 2025
Source filing: View source filing
Reporting owner signature: /s/ Ansbert Gadicke, Manager of MPM Oncology Innovations Fund GP LLC, the GP of MPM Oncology Innovations Fund, L.P.

Key filing fact

Ansbert Gadicke filed Form 4 for Werewolf Therapeutics, Inc. (HOWL) on 20 Nov 2025.

Key facts

This page summarizes Ansbert Gadicke's Form 4 filing for Werewolf Therapeutics, Inc. (HOWL).
3 reported transactions and 0 derivative rows are listed below.
Accepted by SEC: 20 Nov 2025, 17:50.

Change

Previous filing in this sequence was filed on 17 Nov 2025.
Current net transaction value: -$147,913.

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 0001134655 Primary reporting owner

GADICKE ANSBERT

Relationship: 10%+ Owner
Address: C/O MPM BIOIMPACT LLC, 399 BOYLSTON STREET, SUITE 1100, BOSTON
Signature: /s/ Ansbert Gadicke, Manager of MPM Oncology Innovations Fund GP LLC, the GP of MPM Oncology Innovations Fund, L.P.
Signature date: 20 Nov 2025

CIK 0001719960

MPM ONCOLOGY INNOVATIONS FUND LP

Relationship: 10%+ Owner
Address: C/O MPM BIOIMPACT LLC, 399 BOYLSTON STREET, SUITE 1100, BOSTON
Signature: /s/ Ansbert Gadicke, Manager of MPM Oncology Innovations Fund GP LLC
Signature date: 20 Nov 2025

CIK 0001691428

UBS Oncology Impact Fund L.P.

Relationship: 10%+ Owner
Address: C/O MPM BIOIMPACT LLC, 399 BOYLSTON STREET, SUITE 1100, BOSTON
Signature: /s/ Ansbert Gadicke, Managing Partner of MPM BioImpact LLC
Signature date: 20 Nov 2025

CIK 0001721036

Oncology Impact Fund (Cayman) Management L.P.

Relationship: 10%+ Owner
Address: C/O MPM BIOIMPACT LLC, 399 BOYLSTON STREET, SUITE 1100, BOSTON
Signature: /s/ Ansbert Gadicke, member of MPM Asset Management LLC
Signature date: 20 Nov 2025

CIK 0001687078

MPM BioImpact LLC

Relationship: 10%+ Owner
Address: C/O MPM BIOIMPACT LLC, 399 BOYLSTON STREET, SUITE 1100, BOSTON
Signature: /s/ Ansbert Gadicke
Signature date: 20 Nov 2025

CIK 0001857903

MPM Oncology Innovations Fund GP LLC

Relationship: 10%+ Owner
Address: C/O MPM BIOIMPACT LLC, 399 BOYLSTON STREET, SUITE 1100, BOSTON
Signature: /s/ Ansbert Gadicke, Managing Partner of MPM BioImpact LLC, the GP of Oncology Impact Fund (Cayman) Management L.P., the GP of UBS Oncology Impact Fund, L.P.
Signature date: 20 Nov 2025

CIK 0001263048

MPM ASSET MANAGEMENT LLC

Relationship: 10%+ Owner
Address: C/O MPM BIOIMPACT LLC, 399 BOYLSTON STREET, SUITE 1100, BOSTON
Signature: /s/ Ansbert Gadicke, Managing Partner of MPM BioImpact LLC, the GP of Oncology Impact Fund (Cayman) Management L.P.
Signature date: 20 Nov 2025

Reported non-derivative transactions

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

HOWL transaction

Common Stock

Sale

Transaction value: $48,943
Shares: -52,627
Change %: -0.96%
Price: $0.9300
Shares after: 5,428,912
Date: 18 Nov 2025
Ownership: See Footnotes
Footnotes: F1, F2, F3, F4, F5

HOWL transaction

Common Stock

Sale

Transaction value: $62,345
Shares: -66,324
Change %: -1.2%
Price: $0.9400
Shares after: 5,362,588
Date: 19 Nov 2025
Ownership: See Footnotes
Footnotes: F1, F4, F6, F7, F8

HOWL transaction

Common Stock

Sale

Transaction value: $36,625
Shares: -41,152
Change %: -0.77%
Price: $0.8900
Shares after: 5,321,436
Date: 20 Nov 2025
Ownership: See Footnotes
Footnotes: F1, F4, F9, F10, F11

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

Additional SEC filing notes

Filing notes and footnotes

Rule 10b5-1 trading plan

These transactions were reported as open-market trades under a Rule 10b5-1 plan. The plan lets an insider set trading instructions in advance, which can reduce the risk of trading while in possession of material nonpublic information.

Original filing language: transaction made pursuant to a contract, instruction, or written plan intended to satisfy Rule 10b5-1(c).

Explanation of responses 11 footnotes

Footnote F1

Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 dated September 24, 2025.

Footnote F2

The shares were sold as follows: 3,613 by MPM Asset Management LLC ("AM LLC"), 22,827 by MPM BioVentures 2014, L.P. ("BV 2014"), 1,523 by MPM BioVentures 2014(B), L.P. ("BV 2014(B)"), 786 by MPM Asset Management Investors BV2014 LLC ("AM BV2014"), 5,027 by MPM Oncology Innovations Fund, L.P. ("MPM OIF") and 18,851 by UBS Oncology Impact Fund L.P. ("UBS Oncology").

Footnote F3

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.8902 to $0.9601 inclusive. The Reporting Person undertakes 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 sold at each separate price within the range set forth in this footnote.

Footnote F4

MPM BioVentures 2014 GP LLC and MPM BioVentures 2014 LLC ("BV LLC") are the direct and indirect general partners of BV 2014 and BV 2014(B). BV LLC is the manager of AM BV2014. MPM Oncology Innovations Fund GP LLC ("MPM OIF GP") is the general partner of MPM OIF. MPM BioImpact LLC ("BioImpact") is the General Partner of Oncology Impact Fund (Cayman) Management L.P., the General Partner of UBS Oncology. Ansbert Gadicke is a member of AM LLC, a managing director of BV LLC, a manager of MPM OIF GP and the managing partner of BioImpact. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his or its pecuniary interest therein.

Footnote F5

The shares are held as follows: 372,858 by AM LLC, 2,354,688 by BV 2014, 157,054 by BV 2014(B), 81,046 by AM BV2014, 516,458 by MPM OIF and 1,946,808 by UBS Oncology.

Footnote F6

The shares were sold as follows: 4,554 by AM LLC, 28,768 by BV 2014, 1,919 by BV 2014(B), 990 by AM BV2014, 6,335 by MPM OIF and 23,758 by UBS Oncology.

Footnote F7

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.901 to $0.9806 inclusive. The Reporting Person undertakes 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 sold at each separate price within the range set forth in this footnote.

Footnote F8

The shares are held as follows: 368,304 by AM LLC, 2,325,920 by BV 2014, 155,135 by BV 2014(B), 80,056 by AM BV2014, 510,123 by MPM OIF and 1,923,050 by UBS Oncology.

Footnote F9

The shares were sold as follows: 2,825 by AM LLC, 17,850 by BV 2014, 1,191 by BV 2014(B), 614 by AM BV2014, 3,931 by MPM OIF and 14,741 by UBS Oncology.

Footnote F10

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $0.8506 to $0.9556 inclusive. The Reporting Person undertakes 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 sold at each separate price within the range set forth in this footnote.

Footnote F11

The shares are held as follows: 365,479 by AM LLC, 2,308,070 by BV 2014, 153,944 by BV 2014(B), 79,442 by AM BV2014, 506,192 by MPM OIF and 1,908,309 by UBS Oncology.

SEC remarks

This filing is 1 of 2 identical filings due to limitations on number of Reporting Persons. See Form 4 filed by MPM BioVentures 2014, L.P.