Werewolf Therapeutics (ticker: HOWL) holders detail stake and sales in 13D/A

Rhea-AI Filing Summary

MPM-affiliated funds and managers filed Amendment No. 6 to Schedule 13D reporting their ownership of Werewolf Therapeutics, Inc. common stock. Dr. Ansbert Gadicke is reported as beneficially owning 2,608,501 shares, representing 5.4% of the outstanding common stock. The filing cites 48,596,817 shares outstanding as of March 20, 2026.

The group details holdings across multiple entities, including MPM BioVentures 2014, UBS Oncology Impact Fund and related vehicles, with individual funds generally holding between 0.1% and 2.6% of the class. The filing also lists recent open-market sales between April 27 and May 5, 2026 at average prices around $0.69–$0.85 per share by several of these entities.

Key Figures

Shares outstanding: 48,596,817 shares Gadicke beneficial ownership: 2,608,501 shares (5.4%) MPM BioVentures 2014 stake: 1,131,359 shares (2.3%) +4 more

7 metrics

Shares outstanding 48,596,817 shares Common stock outstanding as of March 20, 2026

Gadicke beneficial ownership 2,608,501 shares (5.4%) Werewolf Therapeutics common stock reported in Amendment No. 6

MPM BioVentures 2014 stake 1,131,359 shares (2.3%) Beneficial ownership of common stock by MPM BioVentures 2014, L.P.

UBS Oncology Impact Fund stake 936,031 shares (1.9%) Beneficial ownership of common stock by UBS Oncology Impact Fund L.P.

MPM Oncology Innovations Fund stake 247,526 shares (0.5%) Beneficial ownership of common stock by MPM Oncology Innovations Fund

Sale on April 27, 2026 (BV 2014) 36,488 shares at $0.85 avg Open-market sale by MPM BioVentures 2014, L.P. within $0.818–$0.8788 range

Sale on April 30, 2026 (BV 2014) 113,821 shares at $0.72 avg Open-market sale within $0.688–$0.7458 price range

Key Terms

Schedule 13D, beneficially owned, sole Voting Power, sole Dispositive Power, +2 more

6 terms

Schedule 13D regulatory

"If the filing person has previously filed a statement on Schedule 13D"

A Schedule 13D is a legal document that investors file with regulators when they buy a large enough stake in a company to potentially influence its management or decisions. It provides details about the investor’s intention, ownership stake, and plans, helping other investors understand who is gaining control and what their motives might be.

beneficially owned financial

"for the aggregate number of Common Stock and percentages of the shares of Common Stock beneficially owned"

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

sole Voting Power financial

"Number of Shares Beneficially Owned by Each Reporting Person With: | 7 | Sole Voting Power"

Sole voting power is the exclusive right to cast votes attached to a shareholder’s stock without needing approval from anyone else. Like holding the only remote control for a TV, it lets that holder decide corporate matters such as board members, mergers, and policy changes, making it important to investors because it concentrates control and can strongly influence a company’s strategy and the value of its shares.

sole Dispositive Power financial

"Number of Shares Beneficially Owned by Each Reporting Person With: | 9 | Sole Dispositive Power"

Sole dispositive power is the exclusive legal authority to decide what happens to a security — for example, whether to sell, transfer, or retain shares — without needing anyone else’s permission. Investors care because it signals who truly controls the economic outcome of an investment: like holding the only key to a safe, the holder can realize gains or losses and may trigger regulatory reporting, insider rules, or influence over corporate ownership.

open market financial

"The Reporting Persons sold the following Common Stock in the open market in the last 60 days"

An open market is a system where buying and selling of goods, services, or financial assets happen freely without restrictions or special controls. For investors, it means they can trade assets easily and quickly, which helps determine fair prices based on supply and demand. This environment encourages transparency and competition, making it easier to buy or sell with confidence.

aggregate amount beneficially owned financial

"11Aggregate amount beneficially owned by each reporting person"

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 6)

WEREWOLF THERAPEUTICS, INC.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

95075A107

(CUSIP Number)

Ansbert Gadicke
c/o MPM BioImpact LLC, 339 Boylston Street, Suite 1100
Boston, MA, 02116
617-425-9200

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

05/01/2026

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

schemaVersion:

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

MPM BioVentures 2014, L.P.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 1,131,359.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 1,131,359.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

1,131,359.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

2.3 %

14

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

MPM BioVentures 2014 (B), L.P.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 75,458.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 75,458.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

75,458.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

0.2 %

14

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

MPM Asset Management Investors BV2014 LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 38,939.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 38,939.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

38,939.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

0.1 %

14

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

UBS Oncology Impact Fund L.P.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

CAYMAN ISLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 936,031.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 936,031.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

936,031.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

1.9 %

14

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

MPM BioVentures 2014 GP LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 1,206,817.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 1,206,817.00

11

Aggregate amount beneficially owned by each reporting person

1,206,817.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

2.5 %

14

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

MPM BioVentures 2014 LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 1,245,756.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 1,245,756.00

11

Aggregate amount beneficially owned by each reporting person

1,245,756.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

2.6 %

14

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

Oncology Impact Fund (Cayman) Management L.P.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

CAYMAN ISLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 936,031.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 936,031.00

11

Aggregate amount beneficially owned by each reporting person

936,031.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

1.9 %

14

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

MPM BioImpact LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 936,031.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 936,031.00

11

Aggregate amount beneficially owned by each reporting person

936,031.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

1.9 %

14

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

ANSBERT GADICKE

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 2,608,501.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 2,608,501.00

11

Aggregate amount beneficially owned by each reporting person

2,608,501.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

5.4 %

14

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

LUKE EVNIN

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 1,672,470.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 1,672,470.00

11

Aggregate amount beneficially owned by each reporting person

1,672,470.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

3.4 %

14

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

Todd Foley

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 1,245,756.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 1,245,756.00

11

Aggregate amount beneficially owned by each reporting person

1,245,756.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

2.6 %

14

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

MPM ASSET MANAGEMENT LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 179,188.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 179,188.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

179,188.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

0.4 %

14

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

MPM ONCOLOGY INNOVATIONS FUND LP

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 247,526.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 247,526.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

247,526.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

0.5 %

14

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

MPM Oncology Innovations Fund GP LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

WC

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 247,526.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 247,526.00

11

Aggregate amount beneficially owned by each reporting person

247,526.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

0.5 %

14

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock
(b)	Name of Issuer: WEREWOLF THERAPEUTICS, INC.
(c)	Address of Issuer's Principal Executive Offices: 200 TALCOTT AVENUE, 2ND FLOOR, WATERTOWN, MASSACHUSETTS , 02472.
Item 1 Comment: Explanatory Note: This Amendment No. 6 to Schedule 13D ("Amendment No. 6") is being filed as an amendment to the initial statement on Schedule 13D relating to the common stock (the "Common Stock"), of Werewolf Therapeutics Inc. (the 'Issuer'), as filed with the Securities and Exchange Commission (the "SEC") on May 14, 2021 and as amended by Amendment No. 1 filed November 4, 2025, Amendment No. 2 filed November 17, 2025, Amendment No. 3 filed December 3, 2025, Amendment No. 4 filed December 29, 2025 and Amendment No. 5 filed January 16, 2026 (as amended, the "Original Schedule 13D"). This Schedule 13D/A is being filed by the Filing Persons to report the open market sales of the Issuer's Common Stock by certain Filing Persons. Items 5 and 7 of the Original Schedule 13D are hereby amended and supplemented to the extent hereinafter expressly set forth and, except as amended and supplemented hereby, the Original Schedule 13D remains in full force and effect. All capitalized terms used in this Amendment No. 6 but not defined herein shall have the meanings ascribed thereto in the Original Schedule 13D.
Item 5.	Interest in Securities of the Issuer
(a)	See rows (11) and (13) of the Filing Persons Owner Profile of this Amendment No. 6 for the aggregate number of Common Stock and percentages of the shares of Common Stock beneficially owned by the Filing Person. The Common Stock is held as follows: * 1,131,359 shares are held directly by BV 2014; * 75,458 shares are held directly by BV 2014(B); * 38,939 shares are held directly by AM BV2014 LLC; * 247,526 shares are held directly by MPM OIF; * 179,188 shares by AM LLC; and * 936,031 shares are held directly by UBS Oncology. BV 2014 GP and BV 2014 LLC are the direct and indirect general partners of BV 2014 and BV 2014(B) and, accordingly, may be deemed to beneficially own the shares held by BV 2014 and BV 2014(B). BV 2014 LLC is the managing member of AM BV2014 LLC and, accordingly, may be deemed to beneficially own the shares held by AM BV2014 LLC. MPM OIF GP is the general Partner of MPM OIF and, accordingly, may be deemed to beneficially own the shares held by MPM OIF. BioImpact and Oncology Cayman are the direct and indirect general partners of UBS Oncology and, accordingly, may be deemed to beneficially own the shares held by UBS Oncology. Drs. Gadicke and Evnin and Mr. Foley are the managing directors of BV 2014 LLC and, accordingly, may be deemed to beneficially own the shares held by BV 2014, BV 2014(B) and AM BV2014 LLC. Drs. Gadicke and Evnin are the members of AM LLC and managers of MPM OIF GP and, accordingly, may be deemed to beneficially own the shares held by AM LLC and MPM OIF. Dr. Gadicke is the managing partner of BioImpact and, accordingly may be deemed to beneficially own the shares held by UBS Oncology. Calculation of the percentage of the shares of Common Stock beneficially owned is based upon 48,596,817 shares of Common Stock outstanding as of March 20, 2026, as reported in the Issuer's Form 10-K filed with the SEC on March 27, 2026.
(b)	See rows (7) through (10) of the Filing Persons Owner Profile of this Amendment No. 6 for the number of shares as to which there is sole power to vote or to direct the vote, sole power to dispose or to direct the disposition, or shared power to dispose or to direct the disposition.
(c)	The Reporting Persons sold the following Common Stock in the open market in the last 60 days: Date of Price Range Ave. Price Sold by Sold by Sold By Sold by Sold by Sold by Sale BV 2014 BV AM BV2014 MPM OIF AM LLC UBS 2014(B) LLC Oncology 04/27/26 $0.818-$0.8788 $0.85 36,488 2,434 1,256 7,983 5,779 30,188 04/28/26 $0.673-$0.82 $0.73 64,541 4,305 2,222 14,121 10,223 53,400 04/29/26 $0.68-$0.75 $0.69 38,259 2,552 1,317 8,371 6,060 31,654 04/30/26 $0.688-$0.7458 $0.72 113,821 7,592 3,918 24,903 18,028 94,172 05/01/26 $0.7011-$0.74 $0.73 39,501 2,635 1,360 8,642 6,256 32,682 05/04/26 $0.69-$0.7497 $0.72 32,455 2,164 1,117 7,098 5,139 26,843 05/05/26 $0.6616-$0.7253 $0.69 4,640 310 160 1,015 735 3,840
(d)	Inapplicable.
(e)	Inapplicable.
Item 7.	Material to be Filed as Exhibits.
	Exhibit 99.C - Joint Filing Statement

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

MPM BioVentures 2014, L.P.

Signature:	/s/ Ansbert Gadicke
Name/Title:	Managing Director of MPM BioVentures 2014 LLC, the Managing Member of MPM BioVentures 2014 GP LLC, the General Partner of MPM BioVentures 2014, L.P.
Date:	05/05/2026

MPM BioVentures 2014 (B), L.P.

Signature:	/s/ Ansbert Gadicke
Name/Title:	Managing Director of MPM BioVentures 2014 LLC, Managing Member of MPM BioVentures 2014 GP LLC, the General Partner of MPM BioVentures 2014 (B), L.P.
Date:	05/05/2026

MPM Asset Management Investors BV2014 LLC

Signature:	/s/ Ansbert Gadicke
Name/Title:	Managing Director of MPM BioVentures 2014 LLC, the manager of MPM Asset Management Investors BV2014 LLC
Date:	05/05/2026

UBS Oncology Impact Fund L.P.

Signature:	/s/ Ansbert Gadicke
Name/Title:	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.
Date:	05/05/2026

MPM BioVentures 2014 GP LLC

Signature:	/s/ Ansbert Gadicke
Name/Title:	Managing Director of MPM BioVentures 2014 LLC, the Managing Member of MPM BioVentures 2014 GP LLC
Date:	05/05/2026

MPM BioVentures 2014 LLC

Signature:	/s/ Ansbert Gadicke
Name/Title:	Managing Director
Date:	05/05/2026

Oncology Impact Fund (Cayman) Management L.P.

Signature:	/s/ Ansbert Gadicke
Name/Title:	Managing Partner of MPM BioImpact LLC, the General Partner of Oncology Impact Fund (Cayman) Management L.P.
Date:	05/05/2026

MPM BioImpact LLC

Signature:	/s/ Ansbert Gadicke
Name/Title:	Managing Partner
Date:	05/05/2026

ANSBERT GADICKE

Signature:	/s/ Ansbert Gadicke
Name/Title:	Ansbert Gadicke
Date:	05/05/2026

LUKE EVNIN

Signature:	/s/ Luke Evnin
Name/Title:	Luke Evnin
Date:	05/05/2026

Todd Foley

Signature:	/s/ Todd Foley
Name/Title:	Todd Foley
Date:	05/05/2026

MPM ASSET MANAGEMENT LLC

Signature:	/s/ Ansbert Gadicke
Name/Title:	Member
Date:	05/05/2026

MPM ONCOLOGY INNOVATIONS FUND LP

Signature:	/s/ Ansbert Gadicke
Name/Title:	Manager of MPM Oncology Innovations Fund GP LLC, the General Partner of MPM Oncology Innovations Fund, L.P.
Date:	05/05/2026

MPM Oncology Innovations Fund GP LLC

Signature:	/s/ Ansbert Gadicke
Name/Title:	Manager
Date:	05/05/2026

FAQ

What does the latest Schedule 13D/A filing disclose about HOWL ownership?

The filing shows an investor group led by MPM-related entities reporting beneficial ownership of Werewolf Therapeutics (HOWL) common stock. Dr. Ansbert Gadicke is listed at 2,608,501 shares, or 5.4% of the company’s 48,596,817 outstanding shares as of March 20, 2026.

How many Werewolf Therapeutics (HOWL) shares does Ansbert Gadicke beneficially own?

Ansbert Gadicke is reported as beneficially owning 2,608,501 shares of Werewolf Therapeutics common stock. This stake represents 5.4% of the 48,596,817 shares outstanding as of March 20, 2026, according to the company’s referenced Form 10-K.

Which MPM funds and related entities hold shares of Werewolf Therapeutics (HOWL)?

Holders include MPM BioVentures 2014, L.P., MPM BioVentures 2014 (B), L.P., MPM Asset Management Investors BV2014 LLC, MPM Oncology Innovations Fund, UBS Oncology Impact Fund L.P., and related general partner and management entities, each reporting specific share counts and percentage ownership of HOWL common stock.

What percentage of Werewolf Therapeutics (HOWL) does MPM BioVentures 2014, L.P. hold?

MPM BioVentures 2014, L.P. reports 1,131,359 shares of Werewolf Therapeutics common stock. This position represents 2.3% of the company’s outstanding common stock, based on 48,596,817 shares outstanding as of March 20, 2026, as cited in the filing.

Did the reporting persons recently sell Werewolf Therapeutics (HOWL) shares?

Yes. The filing lists open-market sales of Werewolf Therapeutics common stock between April 27 and May 5, 2026. For example, on April 27, 2026, several funds sold shares at an average price of $0.85 per share within a disclosed intraday price range.

How many HOWL shares does UBS Oncology Impact Fund L.P. beneficially own?

UBS Oncology Impact Fund L.P. reports beneficial ownership of 936,031 shares of Werewolf Therapeutics common stock. This stake represents 1.9% of the 48,596,817 shares outstanding as of March 20, 2026, according to the ownership data in the Schedule 13D/A amendment.