[Form 4] Werewolf Therapeutics, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Werewolf Therapeutics (HOWL) reported insider stock sales by affiliated reporting persons. The group executed open‑market sales under a Rule 10b5‑1 plan dated September 24, 2025. Transactions included 140,488 shares on November 4 at a weighted average price of $1.22, 47,950 shares on November 5 at $1.22, and 54,452 shares on November 6 at $1.21.

Following these trades, the reporting persons collectively reported 5,904,720 shares beneficially owned on an indirect basis. The filing indicates the reporting persons are a director and 10% owner, and that the submission was made by more than one reporting person.

Insights

Insider transactions & governance analyst

Routine insider sales disclosed under a prearranged 10b5‑1 plan; neutral impact.

The filing shows multiple open‑market sales of HOWL common stock by affiliated entities on Nov 4–6, 2025 under a Rule 10b5‑1 plan dated Sep 24, 2025. Reported weighted average prices were $1.22, $1.22, and $1.21, respectively.

Post‑trade, the group reported 5,904,720 shares beneficially owned indirectly. Because these transactions were executed pursuant to a pre‑established plan, they generally signal administrative portfolio activity rather than a change in company fundamentals.

Actual market impact depends on trading volumes and holder decisions. Subsequent filings may provide additional detail on any further plan executions.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

GADICKE ANSBERT

(Last) (First) (Middle)

C/O MPM BIOIMPACT LLC

399 BOYLSTON STREET, SUITE 1100

(Street)

BOSTON MA 02116

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Werewolf Therapeutics, Inc. [ HOWL ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
11/04/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	11/04/2025		S(1)		140,488(2)(3)	D	$1.22(4)	6,007,122	I	See Footnote(5)
Common Stock	11/05/2025		S(1)		47,950(6)	D	$1.22(7)	5,959,172	I	See Footnote(8)
Common Stock	11/06/2025		S(1)		54,452(9)	D	$1.21(10)	5,904,720	I	See Footnote(11)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person^*

GADICKE ANSBERT

(Last) (First) (Middle)

C/O MPM BIOIMPACT LLC

399 BOYLSTON STREET, SUITE 1100

(Street)

BOSTON MA 02116

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

MPM ONCOLOGY INNOVATIONS FUND LP

(Last) (First) (Middle)

C/O MPM BIOIMPACT LLC

399 BOYLSTON STREET, SUITE 1100

(Street)

BOSTON MA 02116

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

UBS Oncology Impact Fund L.P.

(Last) (First) (Middle)

C/O MPM BIOIMPACT LLC

399 BOYLSTON STREET, SUITE 1100

(Street)

BOSTON MA 02116

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Oncology Impact Fund (Cayman) Management L.P.

(Last) (First) (Middle)

C/O MPM BIOIMPACT LLC

399 BOYLSTON STREET, SUITE 1100

(Street)

BOSTON MA 02116

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

MPM BioImpact LLC

(Last) (First) (Middle)

C/O MPM BIOIMPACT LLC

399 BOYLSTON STREET, SUITE 1100

(Street)

BOSTON MA 02116

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

MPM Oncology Innovations Fund GP LLC

(Last) (First) (Middle)

C/O MPM BIOIMPACT LLC

399 BOYLSTON STREET, SUITE 1100

(Street)

BOSTON MA 02116

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

MPM ASSET MANAGEMENT LLC

(Last) (First) (Middle)

C/O MPM BIOIMPACT LLC

399 BOYLSTON STREET, SUITE 1100

(Street)

BOSTON MA 02116

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

Explanation of Responses:

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

2. The shares were sold as follows: 9,645 by MPM Asset Management LLC ("AM LLC"), 60,937 by MPM BioVentures 2014, L.P. ("BV 2014"), 4,064 by MPM BioVentures 2014(B), L.P. (BV 2014(B), 2,098 by MPM Asset Management Investors BV2014 LLC ("AM BV2014"), 13,420 by MPM Oncology Innovations Fund, L.P. ("MPM OIF") and 50,324 by UBS Oncology Impact Fund L.P. ("UBS Oncology"). 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. Ansbert Gadicke is a member of AM LLC, a managing director of BV LLC and a manager of MPM OIF GP. Each Reporting Person disclaims beneficial ownership of the securities except to the extent of his or its pecuniary interest therein.

3. 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 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.

4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $1.17 to $1.30 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.

5. The shares are held as follows: 412,556 by AM LLC, 2,605,487 by BV 2014, 173,782 by BV 2014(B), 89,680 by AM BV2014, 571,690 by MPM OIF and 2,153,927 by UBS Oncology.

6. The shares were sold as follows: 3,292 by AM LLC, 20,798 by BV 2014, 1,387 by BV 2014(B), 717 by AM BV2014, 4,580 by MPM OIF and 17,176 by UBS Oncology.

7. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $1.19 to $1.25 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.

8. The shares are held as follows: 409,264 by AM LLC, 2,584,689 by BV 2014, 172,395 by BV 2014(B), 88,963 by AM BV2014, 567,110 by MPM OIF and 2,136,751 by UBS Oncology.

9. The shares were sold as follows: 3,738 by AM LLC, 23,619 by BV 2014, 1,575 by BV 2014(B), 814 by AM BV2014, 5,201 by MPM OIF and 19,505 by UBS Oncology.

10. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $1.185 to $1.27 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.

11. The shares are held as follows: 405,526 by AM LLC, 2,561,070 by BV 2014, 170,820 by BV 2014(B), 88,149 by AM BV2014, 561,909 by MPM OIF and 2,117,246 by UBS Oncology.

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.

	/s/ Ansbert Gadicke, Manager of MPM Oncology Innovations Fund GP LLC, the GP of MPM Oncology Innovations Fund, L.P.	11/06/2025
	/s/ Ansbert Gadicke, Manager of MPM Oncology Innovations Fund GP LLC	11/06/2025
	/s/ Ansbert Gadicke, Managing Partner of MPM BioImpact LLC	11/06/2025
	/s/ Ansbert Gadicke, member of MPM Asset Management LLC	11/06/2025
	/s/ Ansbert Gadicke	11/06/2025
	/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.	11/06/2025
	/s/ Ansbert Gadicke, Managing Partner of MPM BioImpact LLC, the GP of Oncology Impact Fund (Cayman) Management L.P.	11/06/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did Werewolf Therapeutics (HOWL) insiders report in this Form 4?

Affiliated reporting persons disclosed open‑market sales of common stock on Nov 4–6, 2025 under a Rule 10b5‑1 plan.

How many HOWL shares were sold and at what prices?

Reported sales were 140,488 shares at $1.22 (Nov 4), 47,950 shares at $1.22 (Nov 5), and 54,452 shares at $1.21 (Nov 6), all weighted averages.

What is the remaining beneficial ownership after these transactions for HOWL?

The reporting persons disclosed 5,904,720 shares beneficially owned on an indirect basis after the reported trades.

Were these HOWL insider sales made under a 10b5‑1 plan?

Yes. The transactions were effected pursuant to a Rule 10b5‑1 plan dated September 24, 2025.

What is the relationship of the reporting persons to Werewolf Therapeutics (HOWL)?

The filing indicates the reporting persons are a director and a 10% owner of the issuer.

Was this Form 4 filed by more than one reporting person?

Yes. It was filed by more than one reporting person, reflecting affiliated entities.