CytomX Therapeutics ownership update from Longitude-related entities and principals. The joint filing reports that Longitude Capital Partners V, LLC and Longitude Venture Partners V, L.P. each have shared beneficial ownership of 12,458,461 shares (each 5.7% of the class), and that Longitude 103.8 East entities hold 2,830,000 shares (1.3%). Reporting individuals Patrick G. Enright and Juliet Tammenoms Bakker are each reported with shared beneficial ownership of 15,288,461 shares (7.0% each). The filing cites 217,702,919 shares outstanding as of April 30, 2026 as reported in the issuer’s Form 10-Q.
Positive
None.
Negative
None.
Insights
Large passive stakes by Longitude entities are reported; holdings are cross-attributed through partnerships.
The filing lists shared voting and dispositive power for fund and partner entities: 12,458,461 and 2,830,000 share holdings are recorded under fund entities, producing reported percentages of 5.7% and 1.3% respectively, based on April 30, 2026 outstanding shares.
These positions are shown as held of record by pooled vehicles with managerial attribution to the general partner and managing members. Subsequent disclosures or Form 13D/13G amendments would be the place to watch for changes to group status or control declarations.
Reporting emphasizes shared power via GP/manager relationships rather than direct sole control.
The statements note that LCPV and L103P are general partners and that Patrick G. Enright and Juliet Tammenoms Bakker "may be deemed to share" voting and dispositive power. The filing also disclaims group membership while referencing potential policies linking Seven Fleet to 1,085,398 shares (0.5%).
For governance impact, the cited 7.0% beneficial counts for individuals are material for disclosure thresholds but do not alone indicate control; future filings would clarify any coordinated group activity.
Key Figures
Shares outstanding:217,702,919 sharesLVPV holdings:12,458,461 sharesL103 holdings:2,830,000 shares+3 more
6 metrics
Shares outstanding217,702,919 sharesAs of April 30, 2026
LVPV holdings12,458,461 sharesLongitude Venture Partners V; reported shared voting/dispositive power
L103 holdings2,830,000 sharesLongitude 103.8 East entities; reported shared voting/dispositive power
Enright beneficial ownership15,288,461 sharesAttributed to Patrick G. Enright (combined fund holdings)
Bakker beneficial ownership15,288,461 sharesAttributed to Juliet Tammenoms Bakker (combined fund holdings)
Seven Fleet attributed holdings1,085,398 sharesMay be deemed beneficial owner per disclosed policies (0.5% of class)
"Amount beneficially owned: See Row 9 of the cover page for each Reporting Person."
Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.
dispositive powerregulatory
"Shared Dispositive Power 12,458,461.00"
Dispositive power is the authority to decide the final outcome of an asset, legal claim, contract, or corporate action — in effect the power to dispose of or resolve something. For investors it matters because whoever holds that authority can determine who gets paid, who controls an asset or vote, and how risks and returns are allocated; think of it like holding the key that lets you lock in the winner or loser in a deal.
Section 13(d)(3)regulatory
"may be deemed to be members of a group within the meaning of Section 13(d)(3) of the Exchange Act."
The filing reports 12,458,461 shares held by Longitude Venture Partners V and attributed to related entities, representing 5.7% of the class based on 217,702,919 shares outstanding as of April 30, 2026.
How many shares do Patrick Enright and Juliet Bakker report for CTMX?
Each is attributed with shared beneficial ownership of 15,288,461 shares, equal to 7.0% of the class, based on the issuer’s reported 217,702,919 shares outstanding as of April 30, 2026
Does the filing say these are sole or shared voting powers?
The filing shows 0 sole voting power and lists shared voting and dispositive power for the entities (e.g., 12,458,461 shared for LVPV), attributing control through general partner and managing member roles.
Is there any group affiliation disclosed with other holders in CTMX?
The filing states Seven Fleet may be deemed to own 1,085,398 shares (0.5%) due to policies, but the Reporting Persons expressly disclaim membership in a group under Section 13; the filing does not treat a formal group as admitted.
What outstanding share count does the filing use for CTMX percentages?
Percentages are calculated using 217,702,919 shares outstanding as of April 30, 2026, as reported by the issuer in its Form 10-Q filed on May 7, 2026.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 1)
CytomX Therapeutics, Inc.
(Name of Issuer)
Common Stock, $0.00001 par value per share
(Title of Class of Securities)
23284F105
(CUSIP Number)
03/31/2026
(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)
schemaVersion:
SCHEDULE 13G
CUSIP Number(s):
23284F105
1
Names of Reporting Persons
Longitude Capital Partners V, 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
12,458,461.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
12,458,461.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
12,458,461.00
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)
5.7 %
12
Type of Reporting Person (See Instructions)
OO
Comment for Type of Reporting Person:
All such shares are held of record by LVPV (as defined in Item 2(a) below). LCPV (as defined in Item 2(a) below) is the general partner of LVPV and may be deemed to have voting, investment and dispositive power with respect to these securities. Patrick G. Enright and Juliet Tammenoms Bakker are the managing members of LCPV and may each be deemed to share voting, investment and dispositive power with respect to these securities.
Based on 217,702,919 shares of Common Stock (as defined in Item 2(d) below) outstanding as of April 30, 2026, as reported by the Issuer (as defined in Item 1(a) below) in its quarterly report on Form 10-Q filed with the Securities and Exchange Commission (the Commission) on May 7, 2026 (the Form 10-Q).
SCHEDULE 13G
CUSIP Number(s):
23284F105
1
Names of Reporting Persons
Longitude Venture Partners V, 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
12,458,461.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
12,458,461.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
12,458,461.00
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)
5.7 %
12
Type of Reporting Person (See Instructions)
PN
Comment for Type of Reporting Person:
All such shares are held of record by LVPV. LCPV is the general partner of LVPV and may be deemed to have voting, investment and dispositive power with respect to these securities. Patrick G. Enright and Juliet Tammenoms Bakker are the managing members of LCPV and may each be deemed to share voting, investment and dispositive power with respect to these securities.
Based on 217,702,919 shares of Common Stock outstanding as of April 30, 2026, as reported by the Issuer in the Form 10-Q.
SCHEDULE 13G
CUSIP Number(s):
23284F105
1
Names of Reporting Persons
Longitude 103.8 East Partners, 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
2,830,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
2,830,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
2,830,000.00
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)
1.3 %
12
Type of Reporting Person (See Instructions)
OO
Comment for Type of Reporting Person:
All shares are held of record by L103 (as defined in Item 2(a) below). L103P (as defined in Item 2(a) below) is the general partner of L103 and may be deemed to have voting, investment and dispositive power with respect to these securities. Patrick G. Enright and Juliet Tammenoms Bakker are the managing members of L103P and may each be deemed to share voting, investment and dispositive power with respect to these securities.
Based on 217,702,919 shares of Common Stock outstanding as of April 30, 2026, as reported by the Issuer in the Form 10-Q.
SCHEDULE 13G
CUSIP Number(s):
23284F105
1
Names of Reporting Persons
Longitude 103.8 East, 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
2,830,000.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
2,830,000.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
2,830,000.00
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)
1.3 %
12
Type of Reporting Person (See Instructions)
PN
Comment for Type of Reporting Person:
All shares are held of record by L103. L103P is the general partner of L103 and may be deemed to have voting, investment and dispositive power with respect to these securities. Patrick G. Enright and Juliet Tammenoms Bakker are the managing members of L103P and may each be deemed to share voting, investment and dispositive power with respect to these securities.
Based on 217,702,919 shares of Common Stock outstanding as of April 30, 2026, as reported by the Issuer in the Form 10-Q.
SCHEDULE 13G
CUSIP Number(s):
23284F105
1
Names of Reporting Persons
Patrick G. Enright
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
15,288,461.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
15,288,461.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
15,288,461.00
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)
7.0 %
12
Type of Reporting Person (See Instructions)
IN
Comment for Type of Reporting Person:
Consists of (i) 12,458,461 shares of Common Stock held of record by LVPV, and (ii) 2,830,000 shares of Common Stock held of record by L103. LCPV is the general partner of LVPV and may be deemed to have voting, investment and dispositive power with respect to the shares held of record by LVPV. L103P is the general partner of L103 and may be deemed to have voting, investment and dispositive power with respect to the shares held by L103. Patrick G. Enright and Juliet Tammenoms Bakker are the managing members of each of LCPV and L103P and may each be deemed to share voting, investment and dispositive power with respect to the shares held by LVPV and L103.
Based on 217,702,919 shares of Common Stock outstanding as of April 30, 2026, as reported by the Issuer in the Form 10-Q.
SCHEDULE 13G
CUSIP Number(s):
23284F105
1
Names of Reporting Persons
Juliet Tammenoms Bakker
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
15,288,461.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
15,288,461.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
15,288,461.00
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)
7.0 %
12
Type of Reporting Person (See Instructions)
IN
Comment for Type of Reporting Person:
Consists of (i) 12,458,461 shares of Common Stock held of record by LVPV, and (ii) 2,830,000 shares of Common Stock held of record by L103. LCPV is the general partner of LVPV and may be deemed to have voting, investment and dispositive power with respect to the shares held of record by LVPV. L103P is the general partner of L103 and may be deemed to have voting, investment and dispositive power with respect to the shares held by L103. Patrick G. Enright and Juliet Tammenoms Bakker are the managing members of each of LCPV and L103P and may each be deemed to share voting, investment and dispositive power with respect to the shares held by LVPV and L103.
Based on 217,702,919 shares of Common Stock outstanding as of April 30, 2026, as reported by the Issuer in the Form 10-Q.
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:
This joint statement on Schedule 13G is being filed by Longitude Capital Partners V, LLC (LCPV), Longitude Venture Partners V, L.P. (LVPV), Longitude 103.8 East Partners, LLC (L103P) and Longitude 103.8 East, L.P. (L103, and together with LCPV, LVPV and L103P the Reporting Entities) and Patrick G. Enright and Juliet Tammenoms Bakker (together, the Reporting Individuals). The Reporting Entities and the Reporting Individuals are collectively referred to as the Reporting Persons.
(b)
Address or principal business office or, if none, residence:
The address of the principal business office of each Reporting Person is 2740 Sand Hill Road, 2nd Floor, Menlo Park, CA 94025.
(c)
Citizenship:
LCPV and L103P are each a limited liability company organized under the laws of the State of Delaware. LVPV and L103 are each a limited partnership organized under the laws of the State of Delaware. Each of the Reporting Individuals is a citizen of the United States of America.
(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:
See Row 9 of the cover page for each Reporting Person. LVPV is the record owner of 12,458,461 shares of Common Stock (the LVPV Shares). As general partner of LVPV, LCPV may be deemed to beneficially own the LVPV Shares. L103 is the record owner of 2,830,000 shares of Common Stock (the L103 Shares). As general partner of L103, L103P may be deemed to beneficially own the L103 Shares. Patrick G. Enright and Juliet Tammenoms Bakker are the managing members of LCPV and L103P and may be deemed to share voting, investment and dispositive power with respect to the LVPV Shares and the L103 Shares.
Except to the extent of his, hers, or its pecuniary interest therein, each Reporting Person disclaims beneficial ownership of such shares of Common Stock, except for the shares, if any, such Reporting Person holds of record.
Longitude Capital Management Co., LLC (LCM), the investment advisor of LVPV and L103, and Seven Fleet Advisors LLC (together with its affiliates, Seven Fleet) have instituted policies and procedures that may affect the acquisition, holding and disposition of securities held by Seven Fleet. As a result of such policies and procedures, the Reporting Persons and Seven Fleet may be deemed to be members of a group within the meaning of Section 13(d)(3) of the Exchange Act.
As of the date hereof, based on information provided by or on behalf of Seven Fleet, Seven Fleet may be deemed to be the beneficial owner of 1,085,398 shares of Common Stock, constituting 0.5% of the number of shares of Common Stock based on 217,702,919 shares of Common Stock outstanding as of April 30, 2026, as reported by the Issuer in the Form 10-Q. Notwithstanding such policies and procedures, the Reporting Persons expressly disclaim such group membership and beneficial ownership over any Common Stock that they may be deemed to beneficially own by reason of such policies and procedures. This Schedule 13G shall not be deemed an admission that the Reporting Persons are members of a group for purposes of Section 13 of the Exchange Act or for any other purpose.
(b)
Percent of class:
See Row 11 of the cover page for each Reporting Person and the corresponding footnotes.*
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
See Row 5 of the cover page for each Reporting Person and the corresponding footnotes.*
(ii) Shared power to vote or to direct the vote:
See Row 6 of the cover page for each Reporting Person and the corresponding footnotes.*
(iii) Sole power to dispose or to direct the disposition of:
See Row 7 of the cover page for each Reporting Person and the corresponding footnotes.*
(iv) Shared power to dispose or to direct the disposition of:
See Row 8 of the cover page for each Reporting Person and the corresponding footnotes.*
Item 5.
Ownership of 5 Percent or Less of a Class.
Not Applicable
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.
Under certain circumstances set forth in the limited partnership agreements of LVPV and L103 and the limited liability company agreements of LCPV and L103P, the general and limited partners or members, as the case may be, of each of such entities may be deemed to have the right to receive dividends from, or the proceeds from, the sale of securities of the Issuer owned by each such entity of which they are a partner or member, as the case may be.
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.
Longitude Capital Partners V, LLC
Signature:
/s/ Cristiana Blauth Oliveira
Name/Title:
Cristiana Blauth Oliveira, Authorized Signatory
Date:
05/15/2026
Longitude Venture Partners V, L.P.
Signature:
/s/ Cristiana Blauth Oliveira
Name/Title:
Cristiana Blauth Oliveira, Authorized Signatory
Date:
05/15/2026
Longitude 103.8 East Partners, LLC
Signature:
/s/ Cristiana Blauth Oliveira
Name/Title:
Cristiana Blauth Oliveira, Authorized Signatory
Date:
05/15/2026
Longitude 103.8 East, L.P.
Signature:
By Longitude 103.8 East Partners, LLC, General Partner, /s/ Cristiana Blauth Oliveira
Name/Title:
Cristiana Blauth Oliveira, Authorized Signatory
Date:
05/15/2026
Patrick G. Enright
Signature:
/s/ Cristiana Blauth Oliveira
Name/Title:
Cristiana Blauth Oliveira, as attorney-in-fact for Patrick G. Enright
Date:
05/15/2026
Juliet Tammenoms Bakker
Signature:
/s/ Cristiana Blauth Oliveira
Name/Title:
Cristiana Blauth Oliveira, as attorney-in-fact for Juliet Tammenoms Bakker
