Kyverna Therapeutics, Inc. received an updated ownership report showing that funds affiliated with Westlake BioPartners and Dr. Beth C. Seidenberg beneficially own a significant minority stake in the company’s common stock.
Westlake BioPartners Fund I, L.P. reports beneficial ownership of 3,787,940 shares of Kyverna common stock, representing 6.3% of the class. Westlake BioPartners Opportunity Fund I, L.P. reports 869,317 shares, or 1.5% of the class. In total, Dr. Seidenberg is reported as beneficially owning 4,657,257 shares, or 7.8% of Kyverna’s common stock as of the December 31, 2025 event date.
The filing explains that these shares are held through Westlake limited partnerships, with their respective general partners and Dr. Seidenberg “may be deemed” to have sole voting and dispositive power, while all reporting persons disclaim beneficial ownership beyond their pecuniary interest. The amendment also notes that Dr. Sean E. Harper is no longer a managing director of the general partners and is therefore removed as a reporting person.
Positive
None.
Negative
None.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 1)
Kyverna Therapeutics, Inc.
(Name of Issuer)
Common Stock, par value $0.00001 per share
(Title of Class of Securities)
501976104
(CUSIP Number)
12/31/2025
(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.
501976104
1
Names of Reporting Persons
Westlake BioPartners Fund I, L.P. ("Westlake Fund I")
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
3,787,940.00
6
Shared Voting Power
3,787,940.00
7
Sole Dispositive Power
3,787,940.00
8
Shared Dispositive Power
3,787,940.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
3,787,940.00
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)
6.3 %
12
Type of Reporting Person (See Instructions)
PN
Comment for Type of Reporting Person: Row 5 - 3,787,940 shares, except that Westlake BioPartners GP I, LLC ("Westlake GP I"), the general partner of Westlake BioPartners Fund I, L.P. ("Westlake Fund I"), may be deemed to have sole voting power, and Dr. Beth C. Seidenberg ("Seidenberg"), the managing director of Westlake GP I, may be deemed to have sole power to vote these shares.
Row 7 - 3,787,940 shares, except that Westlake GP I, the general partner of Westlake Fund I, may be deemed to have sole dispositive power, and Seidenberg, the managing director of Westlake GP I, may be deemed to have sole power to dispose of these shares.
SCHEDULE 13G
CUSIP No.
501976104
1
Names of Reporting Persons
Westlake BioPartners GP I, LLC ("Westlake GP I")
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
3,787,940.00
6
Shared Voting Power
3,787,940.00
7
Sole Dispositive Power
3,787,940.00
8
Shared Dispositive Power
3,787,940.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
3,787,940.00
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)
6.3 %
12
Type of Reporting Person (See Instructions)
OO
Comment for Type of Reporting Person: Row 5 - 3,787,940 shares, all of which are owned directly by Westlake Fund I. Westlake GP I, the general partner of Westlake Fund I, may be deemed to have sole voting power, and Seidenberg, the managing director of Westlake GP I, may be deemed to have sole power to vote these shares.
Row 7 - 3,787,940 shares, all of which are owned directly by Westlake Fund I. Westlake GP I, the general partner of Westlake Fund I, may be deemed to have sole dispositive power, and Seidenberg, the managing director of Westlake GP I, may be deemed to have sole power to dispose of these shares.
SCHEDULE 13G
CUSIP No.
501976104
1
Names of Reporting Persons
Westlake BioPartners Opportunity Fund I, L.P. ("Westlake Opportunity Fund I")
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
869,317.00
6
Shared Voting Power
869,317.00
7
Sole Dispositive Power
869,317.00
8
Shared Dispositive Power
869,317.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
869,317.00
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)
1.5 %
12
Type of Reporting Person (See Instructions)
PN
Comment for Type of Reporting Person: Row 5 - 869,317 shares, except that Westlake BioPartners Opportunity GP I, LLC ("Westlake Opportunity GP I"), the general partner of Westlake BioPartners Opportunity Fund I, L.P. ("Westlake Opportunity Fund I"), may be deemed to have sole voting power, and Seidenberg, the managing director of Westlake Opportunity GP I, may be deemed to have sole power to vote these shares.
Row 7 - 869,317 shares, except that Westlake Opportunity GP I, the general partner of Westlake Opportunity Fund I, may be deemed to have sole dispositive power, and Seidenberg, the managing director of Westlake Opportunity GP I, may be deemed to have sole power to dispose of these shares.
SCHEDULE 13G
CUSIP No.
501976104
1
Names of Reporting Persons
Westlake BioPartners Opportunity GP I, LLC ("Westlake Opportunity GP I")
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
869,317.00
6
Shared Voting Power
869,317.00
7
Sole Dispositive Power
869,317.00
8
Shared Dispositive Power
869,317.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
869,317.00
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)
1.5 %
12
Type of Reporting Person (See Instructions)
OO
Comment for Type of Reporting Person: Row 5 - 869,317 shares, all of which are owned directly by Westlake Opportunity Fund I. Westlake Opportunity GP I, the general partner of Westlake Opportunity Fund I, may be deemed to have sole voting power, and Seidenberg, the managing director of Westlake Opportunity GP I, may be deemed to have sole power to vote these shares.
Row 7 - 869,317 shares, all of which are owned directly by Westlake Opportunity Fund I. Westlake Opportunity GP I, the general partner of Westlake Opportunity Fund I, may be deemed to have sole dispositive power, and Seidenberg, the managing director of Westlake Opportunity GP I, may be deemed to have sole power to dispose of these shares.
SCHEDULE 13G
CUSIP No.
501976104
1
Names of Reporting Persons
Dr. Beth C. Seidenberg ("Seidenberg")
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
4,657,257.00
6
Shared Voting Power
4,657,257.00
7
Sole Dispositive Power
4,657,257.00
8
Shared Dispositive Power
4,657,257.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
4,657,257.00
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)
7.8 %
12
Type of Reporting Person (See Instructions)
IN
Comment for Type of Reporting Person: Row 5 - 4,657,257 shares, of which 3,787,940 shares are owned directly by Westlake Fund I and 869,317 shares are owned directly by Westlake Opportunity Fund I. Westlake GP I and Westlake Opportunity GP I, the general partners of Westlake Fund I and Westlake Opportunity Fund I, respectively, may be deemed to have sole voting power over such shares, and Seidenberg, the managing director of Westlake GP I and Westlake Opportunity GP I, may be deemed to have sole power to vote these shares.
Row 7 - 4,657,257 shares, of which 3,787,940 shares are owned directly by Westlake Fund I and 869,317 shares are owned directly by Westlake Opportunity Fund I. Westlake GP I and Westlake Opportunity GP I, the general partners of Westlake Fund I and Westlake Opportunity Fund I, respectively, may be deemed to have sole dispositive power over such shares, and Seidenberg, the managing director of Westlake GP I and Westlake Opportunity GP I, may be deemed to have sole power to dispose of these shares.
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
Kyverna Therapeutics, Inc.
(b)
Address of issuer's principal executive offices:
5980 Horton St., STE 550, Emeryville, CA 94608
Item 2.
(a)
Name of person filing:
This Statement is being filed by Westlake BioPartners Fund I, L.P. ("Westlake Fund I"), Westlake BioPartners GP I, LLC ("Westlake GP I"), Westlake BioPartners Opportunity Fund I, L.P. ("Westlake Opportunity Fund I") and Westlake BioPartners Opportunity GP I, LLC ("Westlake Opportunity GP I" and together with Westlake Fund I, Westlake GP I and Westlake Opportunity Fund I, the "Reporting Entities") and Dr. Beth C. Seidenberg ("Seidenberg") (the "Reporting Individual"). The Reporting Entities and the Reporting Individual are collectively referred to as the "Reporting Persons." Dr. Sean E. Harper, a Reporting Person on the initial Schedule 13G with respect to the Issuer, is no longer a managing director of Westlake GP I and Westlake Opportunity GP I, and accordingly, is not a Reporting Person on this Schedule 13G Amendment No. 1.
(b)
Address or principal business office or, if none, residence:
The address of the principal business office of each Reporting Person is c/o Westlake BioPartners, LLC, 3075 Townsgate Road, Suite 140, Westlake Village, California 91361.
(c)
Citizenship:
Each of Westlake GP I and Westlake Opportunity GP I is a limited liability company organized under the laws of the State of Delaware. Each of Westlake Fund I and Westlake Opportunity Fund I is a limited partnership organized under the laws of the State of Delaware. The Reporting Individual is a citizen of the United States of America.
(d)
Title of class of securities:
Common Stock, par value $0.00001 per share
(e)
CUSIP No.:
501976104
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.*
(b)
Percent of class:
See Row 11 of the cover page for each Reporting Person.*
(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.*
(ii) Shared power to vote or to direct the vote:
See Row 6 of the cover page for each Reporting Person.*
(iii) Sole power to dispose or to direct the disposition of:
See Row 7 of the cover page for each Reporting Person.*
(iv) Shared power to dispose or to direct the disposition of:
See Row 8 of the cover page for each Reporting Person.*
* Except to the extent of a Reporting Person's 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.
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 agreement of each of Westlake Fund I and Westlake Opportunity Fund I and the limited liability company agreement of each of Westlake GP I and Westlake Opportunity GP I, 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:
Not Applicable
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.
Westlake BioPartners Fund I, L.P. ("Westlake Fund I")
Signature:
/s/ Jennifer L. Kercher
Name/Title:
Jennifer L. Kercher/Attorney-in-Fact*, Westlake BioPartners GP I, LLC, Its General Partner
Date:
02/05/2026
Westlake BioPartners GP I, LLC ("Westlake GP I")
Signature:
/s/ Jennifer L. Kercher
Name/Title:
Jennifer L. Kercher/Attorney-in-Fact*
Date:
02/05/2026
Westlake BioPartners Opportunity Fund I, L.P. ("Westlake Opportunity Fund I")
Signature:
/s/ Jennifer L. Kercher
Name/Title:
Jennifer L. Kercher/Attorney-in-Fact*, Westlake BioPartners Opportunity GP I, LLC, Its General Partner
Date:
02/05/2026
Westlake BioPartners Opportunity GP I, LLC ("Westlake Opportunity GP I")
Signature:
/s/ Jennifer L. Kercher
Name/Title:
Jennifer L. Kercher/Attorney-in-Fact*
Date:
02/05/2026
Dr. Beth C. Seidenberg ("Seidenberg")
Signature:
/s/ Jennifer L. Kercher
Name/Title:
Jennifer L. Kercher/Attorney-in-Fact*
Date:
02/05/2026
Comments accompanying signature: * This Schedule 13G was executed pursuant to a Power of Attorney. Note that copies of the applicable Powers of Attorney are included herein as exhibits to this Schedule 13G.
Exhibit Information
Exhibit
1 Joint Filing Agreement
2 Power of Attorney - Westlake BioPartners Fund I, L.P. and Westlake BioPartners GP I, LLC
3 Power of Attorney - Westlake BioPartners Opportunity Fund I, L.P. and Westlake BioPartners Opportunity GP I, LLC
What ownership stake in Kyverna Therapeutics (KYTX) do Westlake funds report?
Westlake BioPartners funds report a combined beneficial stake of 4,657,257 Kyverna shares. This represents 7.8% of Kyverna’s common stock, split between 3,787,940 shares held by Westlake Fund I and 869,317 shares held by Westlake Opportunity Fund I.
How many Kyverna (KYTX) shares does Westlake BioPartners Fund I hold?
Westlake BioPartners Fund I reports beneficial ownership of 3,787,940 Kyverna common shares. This position represents 6.3% of the company’s outstanding common stock, with the fund’s general partner and Dr. Beth C. Seidenberg potentially exercising voting and dispositive power over these shares.
What is Dr. Beth C. Seidenberg’s reported stake in Kyverna Therapeutics (KYTX)?
Dr. Beth C. Seidenberg is reported as beneficially owning 4,657,257 Kyverna shares. This stake equals 7.8% of Kyverna’s common stock and is held through Westlake BioPartners Fund I and Westlake BioPartners Opportunity Fund I, where she is managing director of the general partners.
How many Kyverna (KYTX) shares does Westlake BioPartners Opportunity Fund I own?
Westlake BioPartners Opportunity Fund I reports beneficial ownership of 869,317 Kyverna common shares. These shares represent 1.5% of Kyverna’s common stock, with its general partner and Dr. Beth C. Seidenberg potentially having sole voting and dispositive power over the position.
What change does this Schedule 13G/A report for Kyverna (KYTX)?
The amendment updates the list of reporting persons and current beneficial ownership. It confirms Westlake-affiliated funds and Dr. Beth C. Seidenberg collectively report 7.8% beneficial ownership and notes that Dr. Sean E. Harper is no longer a managing director and thus no longer a reporting person.
Do the Westlake reporting persons fully own all reported Kyverna (KYTX) shares?
The reporting persons disclaim beneficial ownership beyond their pecuniary interest in the Kyverna shares. The filing explains that Westlake limited partnerships directly hold the stock, while their general partners and Dr. Beth C. Seidenberg may be deemed to have voting and dispositive power over those holdings.
