Schedule 13G/A: Suvretta, Averill & Aaron Cowen Disclose CMPX Holdings

Rhea-AI Filing Summary

Compass Therapeutics, Inc. received an amendment to a Schedule 13G reporting that Suvretta Capital Management, LLC, Averill Master Fund, Ltd. and Aaron Cowen together filed ownership information for the issuer's common stock (CUSIP 20454B104). Suvretta reports beneficial ownership of 14,101,159 shares (8.2% of the class) with shared voting and dispositive power. Averill Master Fund reports 12,229,050 shares (7.1%) with shared voting and dispositive power. Aaron Cowen is reported with the same 14,101,159 shares (8.2%). The filing states these securities are directly owned by advisory clients of Suvretta, and the reporting persons disclaim beneficial ownership except to their pecuniary interest.

Positive

• Reported stakes exceed 5%: Suvretta and Aaron Cowen each report 14,101,159 shares (8.2%) and Averill Master Fund reports 12,229,050 shares (7.1%), meeting materiality thresholds.
• Clear disclosure of shared voting and dispositive power for the reported shares, providing transparency about voting influence.
• Filing identifies ownership as held for advisory clients, clarifying that Suvretta's reported securities are client-owned rather than directly proprietary.

Negative

• None.

Insights

Financial Analyst

TL;DR: Passive investors report double-digit aggregated stakes above 7% for Compass Therapeutics, implying notable ownership concentration without stated intent to influence control.

The amendment to Schedule 13G shows Suvretta Capital Management and related reporting persons hold material stakes in Compass Therapeutics: Suvretta and Aaron Cowen each report 14,101,159 shares (8.2%) and Averill Master Fund reports 12,229,050 shares (7.1%). These positions are reported as shared voting and dispositive power and are held on behalf of advisory clients, per the filing. The statement includes the required certification that the holdings were not acquired to change or influence control, consistent with a passive investor filing under Schedule 13G. For investors this documents concentrated ownership by named investment entities but contains no information on purchases, disposition plans, or changes to company strategy.

Corporate Governance Expert

TL;DR: Ownership disclosures exceed the 5% reporting threshold and are filed as passive holdings; no group dissolution or control intent is indicated.

The filing identifies the reporting persons and their jurisdictions, provides exact share counts and percentages (8.2% for Suvretta and Aaron Cowen; 7.1% for Averill Master Fund), and discloses shared voting and dispositive power. Item 6 clarifies that the securities are directly owned by advisory clients of Suvretta, and Item 10 contains the customary certification of non-control purpose. Exhibits A and B are noted for joint filing agreement and control-person identification, but the filing does not provide further details on any coordination beyond the joint filing. From a governance perspective, this is a standard passive disclosure meeting regulatory requirements; it raises the profile of substantial shareholders but does not, on its face, indicate activist intentions.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

Compass Therapeutics, Inc.

(Name of Issuer)

Common Stock, $0.0001 par value per share

(Title of Class of Securities)

20454B104

(CUSIP Number)

08/13/2025

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13G

CUSIP No. 20454B104

1

Names of Reporting Persons

Suvretta Capital Management, LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 14,101,159.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 14,101,159.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

14,101,159.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

8.2 %

12

Type of Reporting Person (See Instructions)

IA, OO

SCHEDULE 13G

CUSIP No. 20454B104

1

Names of Reporting Persons

Averill Master Fund, Ltd.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

CAYMAN ISLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 12,229,050.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 12,229,050.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

12,229,050.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

7.1 %

12

Type of Reporting Person (See Instructions)

CO

SCHEDULE 13G

CUSIP No. 20454B104

1

Names of Reporting Persons

Aaron Cowen

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 14,101,159.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 14,101,159.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

14,101,159.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

8.2 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Compass Therapeutics, Inc.
(b)	Address of issuer's principal executive offices: 80 Guest Street, Suite 601, Boston, MA 02135
Item 2.
(a)	Name of person filing: Suvretta Capital Management, LLC Averill Master Fund, Ltd. Aaron Cowen
(b)	Address or principal business office or, if none, residence: Suvretta Capital Management, LLC 540 Madison Avenue, 7th Floor New York, New York 10022 United States of America Averill Master Fund, Ltd. c/o Maples Corporate Services Limited P.O. Box 309 Ugland House Grand Cayman KY1-1104 Cayman Islands Aaron Cowen c/o Suvretta Capital Management, LLC 540 Madison Avenue, 7th Floor New York, New York 10022 United States of America
(c)	Citizenship: Suvretta Capital Management, LLC - Delaware Averill Master Fund, Ltd. - Cayman Islands Aaron Cowen - United States
(d)	Title of class of securities: Common Stock, $0.0001 par value per share
(e)	CUSIP No.: 20454B104
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: Suvretta Capital Management, LLC - 14,101,159 Averill Master Fund, Ltd. - 12,229,050 Aaron Cowen - 14,101,159
(b)	Percent of class: Suvretta Capital Management, LLC - 8.2% Averill Master Fund, Ltd. - 7.1% Aaron Cowen - 8.2%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: Suvretta Capital Management, LLC - 0 Averill Master Fund, Ltd. - 0 Aaron Cowen - 0
	(ii) Shared power to vote or to direct the vote: Suvretta Capital Management, LLC - 14,101,159 Averill Master Fund, Ltd. - 12,229,050 Aaron Cowen - 14,101,159
	(iii) Sole power to dispose or to direct the disposition of: Suvretta Capital Management, LLC - 0 Averill Master Fund, Ltd. - 0 Aaron Cowen - 0
	(iv) Shared power to dispose or to direct the disposition of: Suvretta Capital Management, LLC - 14,101,159 Averill Master Fund, Ltd. - 12,229,050 Aaron Cowen - 14,101,159
Item 5.	Ownership of 5 Percent or Less of a Class.
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. All of the securities reported in this Schedule 13G Amendment No. 1 are directly owned by advisory clients of Suvretta Capital Management, LLC. None of those advisory clients, other than Averill Master Fund, Ltd., may be deemed to beneficially own more than 5% of the Common Stock, $0.0001 par value per share.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary. Please see Exhibit B attached hereto.
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

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.

Suvretta Capital Management, LLC

Signature:	By: /s/ Andrew Nathanson
Name/Title:	Andrew Nathanson / Authorized Signatory
Date:	08/20/2025

Averill Master Fund, Ltd.

Signature:	By: /s/ Andrew Nathanson
Name/Title:	Andrew Nathanson / Authorized Signatory
Date:	08/20/2025

Aaron Cowen

Signature:	Aaron Cowen
Name/Title:	By: /s/ Aaron Cowen
Date:	08/20/2025

Comments accompanying signature: * Each Reporting Person disclaims beneficial ownership of the reported securities except to the extent of his, her or its pecuniary interest therein, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose. To the extent that "ownership of 5 percent or less of a class" was indicated in Item 5, such response only applies to the Reporting Person(s) that indicated elsewhere herein that it beneficially owns five percent (5%) or less of the class.

Exhibit Information

[Exhibit A - Joint Filing Agreement] [Exhibit B - Control Person Identification]

FAQ

What percent of Compass Therapeutics (CMPX) is reported by Suvretta Capital Management?

Suvretta reports beneficial ownership of 14,101,159 shares, representing 8.2% of the class according to the Schedule 13G/A.

How many shares of CMPX does Averill Master Fund, Ltd. report owning?

Averill Master Fund reports 12,229,050 shares, representing 7.1% of the class per the filing.

Does the Schedule 13G/A state these investors intend to influence control of Compass Therapeutics?

No. The certification in Item 10 states the securities were not acquired and are not held for the purpose of changing or influencing control.

Who signed the Schedule 13G/A for the reporting persons?

Andrew Nathanson signed for Suvretta Capital Management, LLC and Averill Master Fund, Ltd.; Aaron Cowen signed for himself, each dated 08/20/2025.

Are the reported shares held directly or on behalf of others?

The filing states all reported securities are directly owned by advisory clients of Suvretta Capital Management, LLC, and that, except for Averill Master Fund, no advisory client is deemed to beneficially own more than 5%.