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SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549

SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 5)*

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)

01/14/2026 (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).

SCHEDULE 13D

CUSIP No.

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 1,461,054.00 8 Shared Voting Power 0.00 9 Sole Dispositive Power 1,461,054.00 10 Shared Dispositive Power 0.00
11	Aggregate amount beneficially owned by each reporting person 1,461,054.00
12	Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
13	Percent of class represented by amount in Row (11) 3.0 %
14	Type of Reporting Person (See Instructions) PN

SCHEDULE 13D

CUSIP No.

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 97,450.00 8 Shared Voting Power 0.00 9 Sole Dispositive Power 97,450.00 10 Shared Dispositive Power 0.00
11	Aggregate amount beneficially owned by each reporting person 97,450.00
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 No.

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 50,289.00 8 Shared Voting Power 0.00 9 Sole Dispositive Power 50,289.00 10 Shared Dispositive Power 0.00
11	Aggregate amount beneficially owned by each reporting person 50,289.00
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 No.

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 1,208,810.00 8 Shared Voting Power 0.00 9 Sole Dispositive Power 1,208,810.00 10 Shared Dispositive Power 0.00
11	Aggregate amount beneficially owned by each reporting person 1,208,810.00
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) PN

SCHEDULE 13D

CUSIP No.

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 1,558,504.00 9 Sole Dispositive Power 0.00 10 Shared Dispositive Power 1,558,504.00
11	Aggregate amount beneficially owned by each reporting person 1,558,504.00
12	Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
13	Percent of class represented by amount in Row (11) 3.2 %
14	Type of Reporting Person (See Instructions) OO

SCHEDULE 13D

CUSIP No.

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 1,608,793.00 9 Sole Dispositive Power 0.00 10 Shared Dispositive Power 1,608,793.00
11	Aggregate amount beneficially owned by each reporting person 1,608,793.00
12	Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
13	Percent of class represented by amount in Row (11) 3.3 %
14	Type of Reporting Person (See Instructions) OO

SCHEDULE 13D

CUSIP No.

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 1,208,810.00 9 Sole Dispositive Power 0.00 10 Shared Dispositive Power 1,208,810.00
11	Aggregate amount beneficially owned by each reporting person 1,208,810.00
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) PN

SCHEDULE 13D

CUSIP No.

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 1,208,810.00 9 Sole Dispositive Power 0.00 10 Shared Dispositive Power 1,208,810.00
11	Aggregate amount beneficially owned by each reporting person 1,208,810.00
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 No.

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 3,368,670.00 9 Sole Dispositive Power 0.00 10 Shared Dispositive Power 3,368,670.00
11	Aggregate amount beneficially owned by each reporting person 3,368,670.00
12	Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
13	Percent of class represented by amount in Row (11) 6.9 %
14	Type of Reporting Person (See Instructions) IN

SCHEDULE 13D

CUSIP No.

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 2,159,860.00 9 Sole Dispositive Power 0.00 10 Shared Dispositive Power 2,159,860.00
11	Aggregate amount beneficially owned by each reporting person 2,159,860.00
12	Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
13	Percent of class represented by amount in Row (11) 4.4 %
14	Type of Reporting Person (See Instructions) IN

SCHEDULE 13D

CUSIP No.

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 1,608,793.00 9 Sole Dispositive Power 0.00 10 Shared Dispositive Power 1,608,793.00
11	Aggregate amount beneficially owned by each reporting person 1,608,793.00
12	Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
13	Percent of class represented by amount in Row (11) 3.3 %
14	Type of Reporting Person (See Instructions) IN

SCHEDULE 13D

CUSIP No.

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 231,408.00 8 Shared Voting Power 0.00 9 Sole Dispositive Power 231,408.00 10 Shared Dispositive Power 0.00
11	Aggregate amount beneficially owned by each reporting person 231,408.00
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

CUSIP No.

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 319,659.00 8 Shared Voting Power 0.00 9 Sole Dispositive Power 319,659.00 10 Shared Dispositive Power 0.00
11	Aggregate amount beneficially owned by each reporting person 319,659.00
12	Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
13	Percent of class represented by amount in Row (11) 0.7 %
14	Type of Reporting Person (See Instructions) PN

SCHEDULE 13D

CUSIP No.

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 319,659.00 9 Sole Dispositive Power 0.00 10 Shared Dispositive Power 319,659.00
11	Aggregate amount beneficially owned by each reporting person 319,659.00
12	Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)
13	Percent of class represented by amount in Row (11) 0.7 %
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. 5 to Schedule 13D ("Amendment No. 5") 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 and Amendment No. 4 filed December 29, 2025 (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. 5 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. 5 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: * 1,461,054 shares are held directly by BV 2014; * 97,450 shares are held directly by BV 2014(B); * 50,289 shares are held directly by AM BV2014 LLC; * 319,659 shares are held directly by MPM OIF; * 231,408 shares by AM LLC; and * 1,208,810 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 48,540,200 Common Stock outstanding as of October 29, 2025, as reported in the Issuer's Form 10-Q filed with the SEC on November 4, 2025.
(b)	See rows (7) through (10) of the Filing Persons Owner Profile of this Amendment No. 5 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 since the date of filing Amendment No. 4: 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 12/30/25 $0.6085-$0.63 $0.61 23,551 1,571 811 5,186 3,728 19,449 12/31/25 $0.6038-$0.6359 $0.62 16,870 1,125 582 3,715 2,670 13,932 01/02/26 $0.62-$0.6499 $0.63 12,549 837 432 2,764 1,986 10,363 01/05/26 $0.63435-$0.6549 $0.64 12,420 828 429 2,735 1,966 10,257 01/06/26 $0.64-$0.6599 $0.65 27,548 1,837 948 6,067 4,361 22,751 01/07/26 $0.6276-$0.6598 $0.64 8,053 537 277 1,773 1,275 6,651 01/08/26 $0.6243-$0.6368 $0.63 5,215 348 180 1,148 825 4,307 01/09/26 $0.6019-$0.6583 $0.61 16,678 1,112 575 3,673 2,640 13,773 01/12/26 $0.5608-$0.606 $0.57 39,861 2,659 1,373 8,778 6,309 32,919 01/13/26 $0.53675-$0.5697 $0.55 29,195 1,947 1,006 6,429 4,621 24,110 01/14/26 $0.5524-$0.5857 $0.57 20,692 1,380 712 4,557 3,275 17,088 01/15/26 $0.5305-$0.59 $0.55 25,285 1,686 872 5,568 4,002 20,881 01/16/26 $0.535-$0.5495 $0.54 26,213 1,749 893 5,775 4,152 21,647
(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: 01/16/2026

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: 01/16/2026

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: 01/16/2026

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: 01/16/2026

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: 01/16/2026

MPM BioVentures 2014 LLC

Signature: /s/ Ansbert Gadicke Name/Title: Managing Director Date: 01/16/2026

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: 01/16/2026

MPM BioImpact LLC

Signature: /s/ Ansbert Gadicke Name/Title: Managing Partner Date: 01/16/2026

ANSBERT GADICKE

Signature: /s/ Ansbert Gadicke Name/Title: Ansbert Gadicke Date: 01/16/2026

LUKE EVNIN

Signature: /s/ Luke Evnin Name/Title: Luke Evnin Date: 01/16/2026

Todd Foley

Signature: /s/ Todd Foley Name/Title: Todd Foley Date: 01/16/2026

MPM ASSET MANAGEMENT LLC

Signature: /s/ Ansbert Gadicke Name/Title: Member Date: 01/16/2026

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: 01/16/2026

MPM Oncology Innovations Fund GP LLC

Signature: /s/ Ansbert Gadicke Name/Title: Manager Date: 01/16/2026

Joint Filing Statement

I, the undersigned, hereby express my agreement that the attached Schedule 13D (and any amendments thereto) relating to the beneficial ownership by the undersigned of the equity securities of Werewolf Therapeutics, Inc. is filed on behalf of each of the undersigned.

Date: January 16, 2026

MPM BioVentures 2014, L.P.

By:  MPM BioVentures 2014 GP LLC,

        its General Partner

By:  MPM BioVentures 2014 LLC,

        Its Managing Member

By:

/s/ Ansbert Gadicke

Name:   Ansbert Gadicke

Title:     Managing Director

MPM BioVentures 2014 (B), L.P.

By:  MPM BioVentures 2014 GP LLC,

        its General Partner

By:  MPM BioVentures 2014 LLC,

        Its Managing Member

By:

/s/ Ansbert Gadicke

Name:   Ansbert Gadicke

Title:     Managing Director

MPM Asset Management Investors BV 2014 LLC

By: MPM BioVentures 2014 LLC

       Its: Manager

By:

/s/ Ansbert Gadicke

Name:   Ansbert Gadicke

Title:     Managing Director

MPM BioVentures 2014 GP, LLC

By:  MPM BioVentures 2014 LLC,

        Its Managing Member

By:

/s/ Ansbert Gadicke

Name:   Ansbert Gadicke

Title:     Managing Director

MPM BioVentures 2014 LLC

By:

/s/ Ansbert Gadicke

Name:   Ansbert Gadicke

Title:     Managing Director

MPM Asset Management LLC

By:

/s/ Ansbert Gadicke

Name:   Ansbert Gadicke

Title:     Member

MPM Oncology Innovations Fund LP

By:  MPM Oncology Innovations Fund GP LLC

        its General Partner

By:

/s/ Ansbert Gadicke

Name:   Ansbert Gadicke

Title:     Manager

MPM Oncology Innovations Fund GP LLC

By:

/s/ Ansbert Gadicke

Name:   Ansbert Gadicke

Title:     Manager

UBS Oncology Impact Fund, L.P.

By:  Oncology Impact Fund (Cayman) Management L.P.,

        its General Partner

By:  MPM BioImpact LLC,

        Its General Partner

By:

/s/ Ansbert Gadicke

Name:   Ansbert Gadicke

Title:     Managing Partner

Oncology Impact Fund (Cayman) Management L.P.

By:  MPM BioImpact LLC,

        Its General Partner

By:

/s/ Ansbert Gadicke

Name:   Ansbert Gadicke

Title:     Managing Partner

MPM BioImpact LLC

By:

/s/ Ansbert Gadicke

Name:   Ansbert Gadicke

Title:     Managing Partner

By:

/s/ Todd Foley

Name:   Todd Foley

By:

/s/ Luke Evnin

Name:   Luke Evnin

By:

/s/ Ansbert Gadicke

Name:   Ansbert Gadicke