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

Rhea-AI Filing Summary

Biotechnology Value Fund (BVF) and affiliated entities have filed Amendment 4 to a Schedule 13G disclosing their aggregate beneficial ownership of CytomX Therapeutics, Inc. (NASDAQ: CTMX) as of 30 June 2025.

The filing shows that the BVF complex—comprising eight Delaware and Cayman-based funds and general partners plus founder Mark N. Lampert—collectively controls 11,538,462 common shares, or 6.8 % of CytomX’s outstanding stock. The position is held entirely through two series of cash-settled warrants:

• Tranche 1 Warrants: 5,769,231 shares, strike $2.73, expire 3 July 2025.
• Tranche 2 Warrants: 5,769,231 shares, strike $3.77, expire 3 July 2026.

The warrants are subject to a 9.99 % “blocker,” preventing exercise that would take the group’s ownership above that threshold. Current ownership remains below 7 %, therefore none of the warrants are blocked.

Breakdown of key subsidiary holdings:

• Biotechnology Value Fund L.P.: 6,148,026 shares (3.8 % of class)
• Biotechnology Value Fund II L.P.: 4,702,892 shares (2.9 % of class)
• Biotechnology Value Trading Fund OS LP: 541,232 shares (<1 % of class)

BVF GP Holdings LLC (6.4 %) and BVF Partners L.P. (6.8 %) are the primary control entities, with shared voting and dispositive power across the structure. All parties certify the stake is passive and not intended to influence control of CytomX.

The ownership percentages are calculated against 157,544,369 shares reported outstanding in CytomX’s May 13 2025 prospectus plus the warrant shares, where applicable.

Positive

• Smart-money validation: BVF, a respected biotech investor, now holds a sizeable 6.8 % passive stake in CTMX, indicating institutional confidence.

Negative

• Potential dilution: Full exercise of 11.5 m warrants would increase CTMX’s share count by ~7.3 %, pressuring future EPS and ownership percentages.

Insights

Hedge Fund Analyst

TL;DR – BVF’s 6.8 % passive stake via low-strike warrants signals high-conviction upside view but adds potential 7 % dilution.

BVF, a specialist biotech hedge fund, continues to accumulate CytomX through deeply in-the-money Tranche 1 warrants ($2.73 vs. recent $ share price not disclosed) and moderately in-the-money Tranche 2 warrants ($3.77). Exercising both tranches would cost roughly $35 m and $22 m respectively—manageable for BVF’s AUM—suggesting it is prepared to deploy capital quickly if catalysts emerge before July 2025/26 expirations. Because the filing remains on Schedule 13G rather than 13D, BVF affirms a passive stance, limiting governance overhang risk. For existing shareholders, BVF’s presence can be interpreted as smart-money validation, yet full exercise would expand the float by 11.5 m shares (≈7.3 %), a modest but non-trivial dilution.

Corporate Governance Expert

TL;DR – Filing is routine; no intent to seek control, governance impact minimal.

The Amendment 4 simply updates ownership levels following warrant issuance. By retaining Schedule 13G status, BVF certifies it is not engaging in activism. The 9.99 % blocker further limits potential influence. Board composition, voting power, and control remain firmly with existing management and other shareholders.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 4)

CytomX Therapeutics, Inc.

(Name of Issuer)

Common Stock, $0.00001 par value per share

(Title of Class of Securities)

23284F105

(CUSIP Number)

06/30/2025

(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

BIOTECHNOLOGY VALUE FUND L P

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 6,148,026.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 6,148,026.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

6,148,026.00

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)

3.8 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP No. 23284F105

1

Names of Reporting Persons

BVF I GP 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 6,148,026.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 6,148,026.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

6,148,026.00

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)

3.8 %

12

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13G

CUSIP No. 23284F105

1

Names of Reporting Persons

BIOTECHNOLOGY VALUE FUND II LP

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 4,702,892.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 4,702,892.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

4,702,892.00

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)

2.9 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP No. 23284F105

1

Names of Reporting Persons

BVF II GP 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 4,702,892.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 4,702,892.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

4,702,892.00

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)

2.9 %

12

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13G

CUSIP No. 23284F105

1

Names of Reporting Persons

Biotechnology Value Trading Fund OS LP

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 541,232.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 541,232.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

541,232.00

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)

0.3 %

12

Type of Reporting Person (See Instructions)

PN

SCHEDULE 13G

CUSIP No. 23284F105

1

Names of Reporting Persons

BVF Partners OS 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 541,232.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 541,232.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

541,232.00

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)

0.3 %

12

Type of Reporting Person (See Instructions)

CO

SCHEDULE 13G

CUSIP No. 23284F105

1

Names of Reporting Persons

BVF GP HOLDINGS 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 10,850,918.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 10,850,918.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

10,850,918.00

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)

6.4 %

12

Type of Reporting Person (See Instructions)

OO

SCHEDULE 13G

CUSIP No. 23284F105

1

Names of Reporting Persons

BVF PARTNERS L P/IL

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 11,538,462.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 11,538,462.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

11,538,462.00

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)

6.8 %

12

Type of Reporting Person (See Instructions)

IA, PN

SCHEDULE 13G

CUSIP No. 23284F105

1

Names of Reporting Persons

BVF INC/IL

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 11,538,462.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 11,538,462.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

11,538,462.00

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)

6.8 %

12

Type of Reporting Person (See Instructions)

CO

SCHEDULE 13G

CUSIP No. 23284F105

1

Names of Reporting Persons

LAMPERT MARK N

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 11,538,462.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 11,538,462.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

11,538,462.00

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)

6.8 %

12

Type of Reporting Person (See Instructions)

IN

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: Biotechnology Value Fund, L.P. ("BVF") BVF I GP LLC ("BVF GP") Biotechnology Value Fund II, L.P. ("BVF2") BVF II GP LLC ("BVF2 GP") Biotechnology Value Trading Fund OS LP ("Trading Fund OS") BVF Partners OS Ltd. ("Partners OS") BVF GP Holdings LLC ("BVF GPH") BVF Partners L.P. ("Partners") BVF Inc. Mark N. Lampert ("Mr. Lampert") Each of the foregoing is referred to as a "Reporting Person" and collectively as the "Reporting Persons."
(b)	Address or principal business office or, if none, residence: Biotechnology Value Fund, L.P. 44 Montgomery St., 40th Floor San Francisco, California 94104 BVF I GP LLC 44 Montgomery St., 40th Floor San Francisco, California 94104 Biotechnology Value Fund II, L.P. 44 Montgomery St., 40th Floor San Francisco, California 94104 BVF II GP LLC 44 Montgomery St., 40th Floor San Francisco, California 94104 Biotechnology Value Trading Fund OS LP PO Box 309 Ugland House Grand Cayman, KY1-1104 Cayman Islands BVF Partners OS Ltd. PO Box 309 Ugland House Grand Cayman, KY1-1104 Cayman Islands BVF GP Holdings LLC 44 Montgomery St., 40th Floor San Francisco, California 94104 BVF Partners L.P. 44 Montgomery St., 40th Floor San Francisco, California 94104 BVF Inc. 44 Montgomery St., 40th Floor San Francisco, California 94104 Mark N. Lampert 44 Montgomery St., 40th Floor San Francisco, California 94104
(c)	Citizenship: Biotechnology Value Fund, L.P. Delaware BVF I GP LLC Delaware Biotechnology Value Fund II, L.P. Delaware BVF II GP LLC Delaware Biotechnology Value Trading Fund OS LP Cayman Islands BVF Partners OS Ltd. Cayman Islands BVF GP Holdings LLC Delaware BVF Partners L.P. Delaware BVF Inc. Delaware Mark N. Lampert United States
(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: As of the close of business on June 30, 2025, the Reporting Persons and a certain Partners managed account (the "Partners Managed Account") held certain Tranche 1 Warrants (the "Tranche 1 Warrants") exercisable for an aggregate of 5,769,231 Shares. The Tranche 1 Warrants are exercisable at any time at an exercise price of $2.73 per Share and expire on July 3, 2025. The exercise of the Tranche 1 Warrants is subject to the limitations of the Warrants Blocker (as defined below). As of the close of business on June 30, 2025, the Warrants Blocker did not prohibit the exercise of any of the Tranche 1 Warrants held by the Reporting Persons and the Partners Managed Account. As of the close of business on June 30, 2025, the Reporting Persons and the Partners Managed Account held certain Tranche 2 Warrants (the "Tranche 2 Warrants" and together with the Tranche 1 Warrants, the "Warrants") exercisable for an aggregate of 5,769,231 Shares. The Tranche 2 Warrants are exercisable at any time at an exercise price of $3.77 per Share and expire on July 3, 2026. The exercise of the Tranche 2 Warrants is subject to the limitations of the Warrants Blocker. As of the close of business on June 30, 2025, the Warrants Blocker did not prohibit the exercise of any of the Tranche 2 Warrants held by the Reporting Persons and the Partners Managed Account. A holder of Warrants will not have the right to exercise any portion of its Warrants to the extent that the holder (together with its affiliates) would beneficially own more than 9.99% of the Shares outstanding immediately after such exercise (the "Warrants Blocker"). As of the close of business on June 30, 2025, (i) BVF beneficially owned 6,148,026 Shares, consisting of (a) 3,074,013 Shares underlying the Tranche 1 Warrants held by it and (b) 3,074,013 Shares underlying the Tranche 2 Warrants held by it; (ii) BVF2 beneficially owned 4,702,892 Shares, consisting of (a) 2,351,446 Shares underlying the Tranche 1 Warrants held by it and (b) 2,351,446 Shares underlying the Tranche 2 Warrants held by it; and (iii) Trading Fund OS beneficially owned 541,232 Shares, consisting of (a) 270,616 Shares underlying the Tranche 1 Warrants held by it and (b) 270,616 Shares underlying the Tranche 2 Warrants held by it. BVF GP, as the general partner of BVF, may be deemed to beneficially own the 6,148,026 Shares beneficially owned by BVF. BVF2 GP, as the general partner of BVF2, may be deemed to beneficially own the 4,702,892 Shares beneficially owned by BVF2. Partners OS, as the general partner of Trading Fund OS, may be deemed to beneficially own the 541,232 Shares beneficially owned by Trading Fund OS. BVF GPH, as the sole member of each of BVF GP and BVF2 GP, may be deemed to beneficially own the 10,850,918 Shares beneficially owned in the aggregate by BVF and BVF2. Partners, as the investment manager of BVF, BVF2 and Trading Fund OS, and the sole member of Partners OS, may be deemed to beneficially own the 11,538,462 Shares beneficially owned in the aggregate by BVF, BVF2 and Trading Fund OS and held in the Partners Managed Account, including 146,312 Shares held in the Partners Managed Account consisting of (a) 73,156 Shares underlying the Tranche 1 Warrants held by the Partners Managed Account and (b) 73,156 Shares underlying the Tranche 2 Warrants held by the Partners Managed Account. BVF Inc., as the general partner of Partners, may be deemed to beneficially own the 11,538,462 Shares beneficially owned by Partners. Mr. Lampert, as a director and officer of BVF Inc., may be deemed to beneficially own the 11,538,462 Shares beneficially owned by BVF Inc. The foregoing should not be construed in and of itself as an admission by any Reporting Person as to beneficial ownership of any Shares owned by another Reporting Person. BVF GP disclaims beneficial ownership of the Shares beneficially owned by BVF. BVF2 GP disclaims beneficial ownership of the Shares beneficially owned by BVF2. Partners OS disclaims beneficial ownership of the Shares beneficially owned by Trading Fund OS. BVF GPH disclaims beneficial ownership of the Shares beneficially owned by BVF and BVF2. Each of Partners, BVF Inc. and Mr. Lampert disclaims beneficial ownership of the Shares beneficially owned by BVF, BVF2 and Trading Fund OS and held in the Partners Managed Account, and the filing of this statement shall not be construed as an admission that any such person or entity is the beneficial owner of any such securities.
(b)	Percent of class: The following percentages are based upon a denominator that is the sum of: (i) 157,544,369 Shares outstanding as of May 13, 2025, which is the total number of Shares outstanding following the Issuer's public offering as reported in the Issuer's Prospectus filed with the Securities and Exchange Commission on May 12, 2025 and (ii) certain or all of the 11,538,462 Shares underlying the Warrants held by the Reporting Persons and the Partners Managed Account, as applicable. As of the close of business on June 30, 2025, (i) BVF beneficially owned approximately 3.8% of the outstanding Shares, (ii) BVF2 beneficially owned approximately 2.9% of the outstanding Shares, (iii) Trading Fund OS beneficially owned less than 1% of the outstanding Shares, (iv) BVF GP may be deemed to beneficially own approximately 3.8% of the outstanding Shares, (v) BVF2 GP may be deemed to beneficially own approximately 2.9% of the outstanding Shares, (vi) Partners OS may be deemed to beneficially own less than 1% of the outstanding Shares, (vii) BVF GPH may be deemed to beneficially own approximately 6.4% of the outstanding Shares, and (viii) each of Partners, BVF Inc. and Mr. Lampert may be deemed to beneficially own approximately 6.8% of the outstanding Shares (less than 1% of the outstanding Shares are held in the Partners Managed Account).
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: See Cover Pages Items 5-9.
	(ii) Shared power to vote or to direct the vote: See Cover Pages Items 5-9.
	(iii) Sole power to dispose or to direct the disposition of: See Cover Pages Items 5-9.
	(iv) Shared power to dispose or to direct the disposition of: See Cover Pages Items 5-9.
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. BVF GPH, Partners, BVF Inc. and Mr. Lampert share voting and dispositive power over the Shares beneficially owned by BVF and BVF2. Partners, BVF Inc. and Mr. Lampert share voting and dispositive power over the Shares beneficially owned by Trading Fund OS and held in the Partners Managed Account.
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.
	If a group has filed this schedule pursuant to §240.13d-1(b)(1)(ii)(J), so indicate under Item 3(j) and attach an exhibit stating the identity and Item 3 classification of each member of the group. If a group has filed this schedule pursuant to §240.13d-1(c) or §240.13d-1(d), attach an exhibit stating the identity of each member of the group. See Exhibit 99.1 to the Schedule 13G filed with the Securities and Exchange Commission on January 3, 2022.
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.

BIOTECHNOLOGY VALUE FUND L P

Signature:	/s/ Mark N. Lampert
Name/Title:	Mark N. Lampert, Authorized Signatory
Date:	07/09/2025

BVF I GP LLC

Signature:	/s/ Mark N. Lampert
Name/Title:	Mark N. Lampert, Authorized Signatory
Date:	07/09/2025

BIOTECHNOLOGY VALUE FUND II LP

Signature:	/s/ Mark N. Lampert
Name/Title:	Mark N. Lampert, Authorized Signatory
Date:	07/09/2025

BVF II GP LLC

Signature:	/s/ Mark N. Lampert
Name/Title:	Mark N. Lampert, Authorized Signatory
Date:	07/09/2025

Biotechnology Value Trading Fund OS LP

Signature:	/s/ Mark N. Lampert
Name/Title:	Mark N. Lampert, Authorized Signatory
Date:	07/09/2025

BVF Partners OS Ltd.

Signature:	/s/ Mark N. Lampert
Name/Title:	Mark N. Lampert, Authorized Signatory
Date:	07/09/2025

BVF GP HOLDINGS LLC

Signature:	/s/ Mark N. Lampert
Name/Title:	Mark N. Lampert, Authorized Signatory
Date:	07/09/2025

BVF PARTNERS L P/IL

Signature:	/s/ Mark N. Lampert
Name/Title:	Mark N. Lampert, Authorized Signatory
Date:	07/09/2025

BVF INC/IL

Signature:	/s/ Mark N. Lampert
Name/Title:	Mark N. Lampert, Authorized Signatory
Date:	07/09/2025

LAMPERT MARK N

Signature:	/s/ Mark N. Lampert
Name/Title:	Mark N. Lampert
Date:	07/09/2025

FAQ

How much of CytomX (CTMX) stock does Biotechnology Value Fund currently own?

As of 30 June 2025, BVF and affiliates beneficially own 11,538,462 shares, or 6.8 % of CTMX’s outstanding common stock.

What type of securities does BVF hold in CTMX?

BVF’s position is entirely in two tranches of cash-settled warrants totaling 11.54 m underlying shares.

What are the strike prices and expirations of the CTMX warrants held by BVF?

Tranche 1: strike $2.73, expires 3 July 2025; Tranche 2: strike $3.77, expires 3 July 2026.

Does BVF intend to influence control of CytomX?

No. The Schedule 13G certification states the securities are not held for the purpose of changing or influencing control of CytomX.

What is the 9.99 % warrant blocker mentioned in the filing?

The blocker prevents BVF and its affiliates from exercising warrants if it would push their ownership above 9.99 % of CTMX’s shares.

How many shares are outstanding for CytomX according to the filing?

The denominator used is 157,544,369 shares outstanding as reported in CytomX’s 12 May 2025 prospectus.