RA Capital funds sell HOWL shares, report 12.6% Werewolf Therapeutics stake

Rhea-AI Filing Summary

RA Capital Management and affiliated funds report beneficial ownership of 6,116,140 shares of Werewolf Therapeutics common stock, equal to 12.6% of the company, based on 48,596,817 shares outstanding as of May 1, 2026. Most of these shares, 5,709,858 or 11.7% of the class, are held by RA Capital Healthcare Fund, with the balance held by RA Capital Nexus Fund II. RA Capital has delegated voting and investment authority over the funds’ holdings and may be deemed a beneficial owner for Section 13(d) purposes, while the funds themselves disclaim beneficial ownership. The amendment also details recent open market sales by the Fund and Nexus Fund II from May 8 to May 12, 2026 at weighted average prices between $0.64 and $0.71 per share, and notes that the reported ownership percentages reflect an increase in the issuer’s outstanding shares.

Key Figures

Beneficial ownership: 6,116,140 shares Ownership percentage: 12.6% Fund holdings: 5,709,858 shares +5 more

8 metrics

Beneficial ownership 6,116,140 shares Shares of Werewolf Therapeutics common stock beneficially owned by reporting persons

Ownership percentage 12.6% Portion of Werewolf Therapeutics common stock class beneficially owned

Fund holdings 5,709,858 shares Werewolf Therapeutics shares held by RA Capital Healthcare Fund, 11.7% of class

Shares outstanding 48,596,817 shares Werewolf Therapeutics common stock outstanding as of May 1, 2026

May 8, 2026 Fund sale 351,514 shares at $0.71 Open market sale by RA Capital Healthcare Fund, weighted average price

May 8, 2026 Nexus sale 25,012 shares at $0.71 Open market sale by RA Capital Nexus Fund II, weighted average price

May 12, 2026 Fund sale 94,432 shares at $0.64 Open market sale by RA Capital Healthcare Fund, weighted average price

May 12, 2026 Nexus sale 6,719 shares at $0.64 Open market sale by RA Capital Nexus Fund II, weighted average price

Key Terms

beneficial owner, Schedule 13D/A, open market sale, shared voting power, +2 more

6 terms

beneficial owner financial

"may be deemed a beneficial owner, for purposes of Section 13(d) of the Securities Exchange Act of 1934"

A beneficial owner is the person who ultimately owns or controls a financial asset or property, even if their name isn't directly on official documents. Think of it like someone who secretly holds the keys to a safe deposit box—others may appear to have access, but the true owner is the one who benefits from what's inside. Identifying beneficial owners helps ensure transparency and prevent illegal activities like money laundering or fraud.

Schedule 13D/A regulatory

"to file this Schedule 3D/A jointly in accordance with Rule 13d-1(k) of the Securities Exchange Act"

A Schedule 13D/A is an amended disclosure filed with regulators by an investor who already reported owning more than 5% of a company’s shares and needs to update their original filing. Think of it as a public status update that tells markets whether the investor’s ownership, plans, or source of funds have changed; such updates matter because they can signal a push for control, major strategic moves, or increased pressure on management, which can affect stock prices.

open market sale financial

"Open Market Sale Fund 05/08/2026 351,514 0.71 0.69 0.76"

An open market sale is when a company or a shareholder sells shares through the regular stock market to any willing buyer, using ordinary exchange trading rather than private deals. It matters to investors because it increases the number of shares available and can push the price down or change ownership balance—think of it like someone putting extra items on a supermarket shelf for any shopper to buy, which can lower the item's price if supply suddenly grows.

shared voting power financial

"Shared Voting Power 6,116,140.00"

Shared voting power occurs when two or more parties jointly have the right to vote or decide how a block of company shares is cast, like co-owners who must agree before moving a piece of furniture. Investors care because who controls voting rights affects board elections, major corporate decisions and takeover outcomes, and shared control can alter regulatory disclosures and the practical influence any holder has over a company’s direction and value.

shared dispositive power financial

"Shared Dispositive Power 6,116,140.00"

investment adviser financial

"RA Capital serves as investment adviser for the Fund and the Nexus Fund II"

An investment adviser is a person or firm that professionally manages money and gives recommendations about buying, selling, or holding investments. Like a financial coach or guide, they have a legal duty to act in a client's best financial interest, so their advice, fees and potential conflicts can directly affect returns and risk — making their role important for investors who want informed, accountable help with portfolios.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 8)

WEREWOLF THERAPEUTICS, INC.

(Name of Issuer)

Common Stock, $0.0001 par value per share

(Title of Class of Securities)

95075A107

(CUSIP Number)

Peter Kolchinsky
RA Capital Management, L.P., 200 Berkeley Street, 18th Floor
Boston, MA, 02116
617.778.2500

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

05/12/2026

(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

RA Capital 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)

AF

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 6,116,140.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 6,116,140.00

11

Aggregate amount beneficially owned by each reporting person

6,116,140.00

12

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

13

Percent of class represented by amount in Row (11)

12.6 %

14

Type of Reporting Person (See Instructions)

IA, PN

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

Peter Kolchinsky

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)

AF

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 6,116,140.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 6,116,140.00

11

Aggregate amount beneficially owned by each reporting person

6,116,140.00

12

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

13

Percent of class represented by amount in Row (11)

12.6 %

14

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

Rajeev Shah

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)

AF, OO

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 6,116,140.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 6,116,140.00

11

Aggregate amount beneficially owned by each reporting person

6,116,140.00

12

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

13

Percent of class represented by amount in Row (11)

12.6 %

14

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13D

CUSIP Number(s): 95075A107

1

Name of reporting person

RA Capital Healthcare 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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 5,709,858.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 5,709,858.00

11

Aggregate amount beneficially owned by each reporting person

5,709,858.00

12

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

13

Percent of class represented by amount in Row (11)

11.7 %

14

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, $0.0001 par value per share
(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: Item 1 of the Statement is amended and supplemented as follows: This Amendment No. 8 (this "Amendment No. 8" or this "Schedule 13D/A") amends and supplements the statement on Schedule 13D originally filed with the Securities and Exchange Commission (the "SEC") on May 6, 2021, and amended on June 16, 2021, August 12, 2022, January 10, 2023, February 14, 2024, May 7, 2024, May 14, 2025 and November 6, 2025 (as amended, the "Statement") by the Reporting Persons. Unless otherwise defined herein, capitalized terms used in this Amendment No. 8 shall have the meanings ascribed to them in the Statement. Unless amended or supplemented below, the information in the Statement remains unchanged.
Item 2.	Identity and Background
(a)	This Schedule 13D/A is being filed on behalf of RA Capital Management, L.P. ("RA Capital"), Peter Kolchinsky, Rajeev Shah, and RA Capital Healthcare Fund, L.P. (the "Fund"), who are collectively referred to herein as the "Reporting Persons." The agreement among the Reporting Persons to file this Schedule 3D/A jointly in accordance with Rule 13d-1(k) of the Securities Exchange Act of 1934, as amended (the "Act"), is attached hereto as Exhibit 99.1. The Reporting Persons' ownership of the Issuer's securities includes (i) 5,709,858 shares of common stock held directly by the Fund and (ii) 406,282 shares of common stock held by RA Capital Nexus Fund II, L.P. (the "Nexus Fund II"). RA Capital Healthcare Fund GP, LLC is the general partner of the Fund and RA Capital Nexus Fund II GP, LLC is the general partner of the Nexus Fund II. The general partner of RA Capital is RA Capital Management GP, LLC, of which Dr. Kolchinsky and Mr. Shah are the controlling persons. RA Capital serves as investment adviser for the Fund and the Nexus Fund II and may be deemed a beneficial owner, for purposes of Section 13(d) of the Securities Exchange Act of 1934 (the "Act"), of any securities of the Issuer held by the Fund or the Nexus Fund II. The Fund and the Nexus Fund II have delegated to RA Capital the sole power to vote and the sole power to dispose of all securities held in the Fund's and the Nexus Fund II's portfolio, including the shares of the Issuer's common stock reported herein. Because the Fund and the Nexus Fund II have divested themselves of voting and investment power over the reported securities they hold and may not revoke that delegation on less than 61 days' notice, the Fund and the Nexus Fund II disclaim beneficial ownership of the securities they hold for purposes of Section 13(d) of the Act and therefore disclaim any obligation to report ownership of the reported securities under Section 13(d) of the Act. As managers of RA Capital, Dr. Kolchinsky and Mr. Shah may be deemed beneficial owners, for purposes of Section 13(d) of the Act, of any securities of the Issuer beneficially owned by RA Capital. RA Capital, Dr. Kolchinsky, and Mr. Shah disclaim beneficial ownership of the securities reported in this Schedule 13D/A other than for the purpose of determining their obligations under Section 13(d) of the Act, and the filing of this Schedule 13D/A shall not be deemed an admission that either RA Capital, Dr. Kolchinsky, or Mr. Shah is the beneficial owner of such securities for any other purpose.
(b)	The address of the principal business office of each of the Reporting Persons is 200 Berkeley Street, 18th Floor, Boston, MA 02116.
(c)	The Fund is a private investment vehicle. RA Capital provides investment management services to the Fund and the Nexus Fund II. The principal occupation of Dr. Kolchinsky and Mr. Shah is investment management.
(d)	During the last five years, none of the Reporting Persons has been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).
(e)	During the last five years, none of the Reporting Persons has been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree of final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.
(f)	See Item 6 of the cover pages.
Item 5.	Interest in Securities of the Issuer
(a)	Rows 11 and 13 of each Reporting Person's cover page to this Schedule 13D/A set forth the aggregate number of shares of common stock and percentages of the shares of common stock beneficially owned by such Reporting Person and are incorporated by reference. The percentage set forth in each row 13 is based upon 48,596,817 shares of common stock outstanding as of May 1, 2026, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the SEC on May 7, 2026.
(b)	Rows 7 through 10 of each Reporting Person's cover page to this Schedule 13D/A set forth the number of shares of common stock as to which such Reporting Person has the sole or shared power to vote or direct the vote and sole or shared power to dispose or to direct the disposition and are incorporated by reference.
(c)	No transactions with respect to the securities of the Issuer have been effected during the past sixty days by any Reporting Person. The percentage ownership reported in this amendment reflect an increase in the number of outstanding shares of the Issuer.
(d)	Except as set forth below, none of the Reporting Persons has effected any transactions with respect to the securities of the Issuer since the most recent amendment to this Schedule 13D/A. Weighted Low High No. Average Price Price Transaction Seller Date Shares Price ($) ($) ($) Open Market Sale Fund 05/08/2026 351,514 0.71 0.69 0.76 Open Market Sale Nexus Fund II 05/08/2026 25,012 0.71 0.69 0.76 Open Market Sale Fund 05/11/2026 81,678 0.67 0.66 0.71 Open Market Sale Nexus Fund II 05/11/2026 5,812 0.67 0.66 0.71 Open Market Sale Fund 05/12/2026 94,432 0.64 0.62 0.65 Open Market Sale Nexus Fund II 05/12/2026 6,719 0.64 0.62 0.65
(e)	Not applicable.
Item 7.	Material to be Filed as Exhibits.
	Exhibit 99.1 Joint Filing Agreement (incorporated by reference to Exhibit 99.1 to the Reporting Persons' Schedule 13D/A filed with the SEC on May 14, 2025).

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.

RA Capital Management, L.P.

Signature:	/s/ Peter Kolchinsky
Name/Title:	By Peter Kolchinsky, Authorized Signatory
Date:	05/14/2026

Peter Kolchinsky

Signature:	/s/ Peter Kolchinsky
Name/Title:	Peter Kolchinsky
Date:	05/14/2026

Rajeev Shah

Signature:	/s/ Rajeev Shah
Name/Title:	Rajeev Shah
Date:	05/14/2026

RA Capital Healthcare Fund, L.P.

Signature:	/s/ Peter Kolchinsky
Name/Title:	By RA Capital Healthcare Fund GP, LLC, its General Partner, By Peter Kolchinsky, Manager
Date:	05/14/2026

FAQ

How much of Werewolf Therapeutics (HOWL) does RA Capital currently own?

RA Capital and affiliated reporting persons beneficially own 6,116,140 shares of Werewolf Therapeutics common stock, representing 12.6% of the company, based on 48,596,817 shares outstanding as of May 1, 2026, according to the amended beneficial ownership report.

Which RA Capital funds hold Werewolf Therapeutics (HOWL) shares and how many?

The filing states RA Capital Healthcare Fund directly holds 5,709,858 shares of Werewolf Therapeutics, representing 11.7% of the outstanding common stock. RA Capital Nexus Fund II holds an additional 406,282 shares, with RA Capital acting as investment adviser and exercising delegated voting and investment authority.

What recent trading in Werewolf Therapeutics (HOWL) shares did RA Capital funds disclose?

The report lists open market sales by RA Capital Healthcare Fund and RA Capital Nexus Fund II between May 8 and May 12, 2026, including blocks such as 351,514 shares at a weighted average price of $0.71 and 94,432 shares at $0.64, within stated daily price ranges.

Why did RA Capital file this Amendment No. 8 related to Werewolf Therapeutics (HOWL)?

Amendment No. 8 updates an existing beneficial ownership statement originally filed in 2021 to reflect current holdings, recent open market sales by RA Capital funds, and revised ownership percentages, which are calculated using 48,596,817 outstanding shares as reported in Werewolf Therapeutics’ May 2026 Form 10-Q.

How are voting and investment powers over Werewolf Therapeutics (HOWL) shares structured for RA Capital?

The funds have delegated sole voting and dispositive power over their Werewolf Therapeutics holdings to RA Capital, which serves as investment adviser. Because this authority cannot be revoked on less than 61 days’ notice, the funds disclaim beneficial ownership for Section 13(d) purposes, while RA Capital and its managers may be deemed beneficial owners.

Did RA Capital indicate why percentage ownership in Werewolf Therapeutics (HOWL) changed?

The filing explains that the percentage ownership figures reflect an increase in Werewolf Therapeutics’ outstanding shares. This change in the denominator, together with the disclosed open market sales, affects the reported percentages while the absolute share count held by RA Capital-related entities remains clearly quantified.