[SCHEDULE 13G] CytomX Therapeutics, Inc. SEC Filing

Rhea-AI Filing Summary

Perceptive Advisors, Joseph Edelman and Perceptive Life Sciences Master Fund report a shared beneficial ownership stake of 9,680,185 shares in CytomX Therapeutics, representing 5.9% of the outstanding common stock based on 164,912,906 shares outstanding. The Master Fund directly holds the shares, while Perceptive Advisors, as investment manager, and Mr. Edelman, as managing member, may be deemed to beneficially own those shares. All three reporting persons disclose no sole voting or dispositive power and shared voting and dispositive power over the reported shares.

Positive

• Material stake disclosed: 9,680,185 shares representing 5.9% of outstanding common stock, improving transparency for investors
• Clear ownership structure: Master Fund directly holds the shares while Perceptive Advisors and Joseph Edelman are identified as manager and managing member, clarifying relationships
• Shared (not sole) power disclosed: Reporting persons state 0 sole voting/dispositive power and full shared voting/dispositive power, indicating no unilateral control

Negative

• None.

Insights

Securities/Investment Analyst

TL;DR: A disclosed 5.9% stake by a named investment manager and affiliated fund is material and increases investor transparency.

The filing shows Perceptive Life Sciences Master Fund directly holds 9,680,185 shares (5.9% of the class). Perceptive Advisors, as investment manager, and Joseph Edelman, as managing member, report shared voting and dispositive power only, with zero sole power. This structure aligns with typical manager/fund relationships where the manager is deemed to beneficially own fund holdings. The disclosure uses the issuer's reported share count (164,912,906) to calculate the percentage, providing clear context for the stake size.

Corporate Governance Expert

TL;DR: The report is a routine institutional disclosure that confirms collective influence but indicates no unilateral control.

The submission identifies the reporting persons and their places of organization and clarifies that voting and disposition are shared, not sole. That distinction matters for governance: shared power signals potential collaboration or internal allocation of authority rather than immediate control actions. The certification states the securities were not acquired to change or influence control, consistent with a passive 13G disclosure rather than an active 13D assertion.

08/21/2025 - 04:00 PM

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

CytomX Therapeutics, Inc.

(Name of Issuer)

Common Stock, $0.00001 par value per share

(Title of Class of Securities)

23284F105

(CUSIP Number)

08/14/2025

(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. 23284F105

1

Names of Reporting Persons

Perceptive Advisors 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 9,680,185.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 9,680,185.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

9,680,185.00

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)

5.9 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

CUSIP No. 23284F105

1

Names of Reporting Persons

Joseph Edelman

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 9,680,185.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 9,680,185.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

9,680,185.00

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)

5.9 %

12

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13G

CUSIP No. 23284F105

1

Names of Reporting Persons

Perceptive Life Sciences 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 9,680,185.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 9,680,185.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

9,680,185.00

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)

5.9 %

12

Type of Reporting Person (See Instructions)

CO

SCHEDULE 13G

Item 1.
(a)	Name of issuer: CytomX Therapeutics, Inc.
(b)	Address of issuer's principal executive offices: 151 Oyster Point Blvd., Suite 400, South San Francisco, CA 94080
Item 2.
(a)	Name of person filing: The names of the persons filing this report (collectively, the "Reporting Persons") with respect to shares of Common Stock, par value $0.00001 per share (the "Common Stock") of CytomX Therapeutics, Inc. (the "Issuer") are: Perceptive Advisors LLC ("Perceptive Advisors") Joseph Edelman ("Mr. Edelman") Perceptive Life Sciences Master Fund, Ltd. (the "Master Fund")
(b)	Address or principal business office or, if none, residence: The address of the principal business office of each of the Reporting Persons is: 51 Astor Place, 10th Floor New York, NY 10003
(c)	Citizenship: Perceptive Advisors is a Delaware limited liability company Mr. Edelman is a United States citizen The Master Fund is a Cayman Islands corporation
(d)	Title of class of securities: Common Stock, $0.00001 par value per share
(e)	CUSIP No.: 23284F105
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: The information required by this item with respect to each Reporting Person is set forth in Rows 5 through 9 and 11 of the cover pages to this Schedule 13G. The ownership percentages reported are based on 164,912,906 outstanding shares of Common Stock as of July 31, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on August 7, 2025. The Master Fund directly holds 9,680,185 shares of Common Stock. Perceptive Advisors serves as the investment manager to the Master Fund and may be deemed to beneficially own the securities directly held by the Master Fund. Mr. Edelman is the managing member of Perceptive Advisors and may be deemed to beneficially own the securities directly held by the Master Fund.
(b)	Percent of class: Perceptive Advisors: 5.9% Mr. Edelman: 5.9% Master Fund: 5.9%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: Perceptive Advisors: 0 Mr. Edelman: 0 Master Fund: 0
	(ii) Shared power to vote or to direct the vote: Perceptive Advisors: 9,680,185 Mr. Edelman: 9,680,185 Master Fund: 9,680,185
	(iii) Sole power to dispose or to direct the disposition of: Perceptive Advisors: 0 Mr. Edelman: 0 Master Fund: 0
	(iv) Shared power to dispose or to direct the disposition of: Perceptive Advisors: 9,680,185 Mr. Edelman: 9,680,185 Master Fund: 9,680,185
Item 5.	Ownership of 5 Percent or Less of a Class.
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
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.

Perceptive Advisors LLC

Signature:	/s/ Joseph Edelman
Name/Title:	Joseph Edelman, Managing Member
Date:	08/21/2025

Joseph Edelman

Signature:	/s/ Joseph Edelman
Name/Title:	Joseph Edelman
Date:	08/21/2025

Perceptive Life Sciences Master Fund, Ltd.

Signature:	/s/ Joseph Edelman
Name/Title:	Joseph Edelman, Managing Member
Date:	08/21/2025

FAQ

What stake does Perceptive Advisors/Perceptive Life Sciences Master Fund hold in CytomX (CTMX)?

They report beneficial ownership of 9,680,185 shares, equal to 5.9% of CytomX's outstanding common stock based on 164,912,906 shares.

Who is reported as having shared voting and disposition power over the CTMX shares?

Perceptive Advisors, Joseph Edelman, and Perceptive Life Sciences Master Fund each report shared voting and shared dispositive power over the 9,680,185 shares and no sole voting or dispositive power.

Does the filing indicate the shares were acquired to change control of CytomX (CTMX)?

No. The certification states the securities were not acquired and are not held for the purpose of changing or influencing control of the issuer, consistent with a Schedule 13G filing.

Which entity directly holds the reported CTMX shares?

The filing states the Perceptive Life Sciences Master Fund, Ltd. directly holds the 9,680,185 shares; Perceptive Advisors serves as the fund's investment manager.

How was the 5.9% ownership percentage calculated?

The percentage is based on 164,912,906 outstanding shares of common stock as reported by the issuer in its quarterly report.