EcoR1 reports 6.4% Xencor (XNCR) stake in updated ownership filing

Rhea-AI Filing Summary

EcoR1 Capital and related parties report a sizable passive stake in Xencor Inc. EcoR1 Capital, LLC and Oleg Nodelman each report beneficial ownership of 4,640,000 Xencor common shares, representing 6.4% of the class, including both common stock and warrants. EcoR1 Capital Fund Qualified, L.P. reports beneficial ownership of 4,354,981 shares, or 6.0% of the class. These percentages are based on 71,410,469 common shares outstanding as of October 30, 2025, as cited from Xencor’s Form 10‑Q. The reporting persons state the securities were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control of Xencor.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 5)

Xencor Inc

(Name of Issuer)

Common Stock

(Title of Class of Securities)

98401F105

(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. 98401F105

1

Names of Reporting Persons

EcoR1 Capital, 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 4,640,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 4,640,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

4,640,000.00

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)

6.4 %

12

Type of Reporting Person (See Instructions)

IA, OO

Comment for Type of Reporting Person: Percentage calculated based (1) 3,251,112 shares of Common Stock beneficially owned by the reporting person and warrants to acquire 1,388,888 shares of Common Stock beneficially owned by the reporting person, and (2) on 71,410,469 shares of Common Stock outstanding on October 30, 2025, as reported in the Form 10-Q filed by the Issuer for the quarter ended September 30, 2025.

SCHEDULE 13G

CUSIP No. 98401F105

1

Names of Reporting Persons

Oleg Nodelman

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 4,640,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 4,640,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

4,640,000.00

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)

6.4 %

12

Type of Reporting Person (See Instructions)

HC, IN

Comment for Type of Reporting Person: Percentage calculated based (1) 3,251,112 shares of Common Stock beneficially owned by the reporting person and warrants to acquire 1,388,888 shares of Common Stock beneficially owned by the reporting person, and (2) on 71,410,469 shares of Common Stock outstanding on October 30, 2025, as reported in the Form 10-Q filed by the Issuer for the quarter ended September 30, 2025.

SCHEDULE 13G

CUSIP No. 98401F105

1

Names of Reporting Persons

EcoR1 Capital Fund Qualified, 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 4,354,981.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 4,354,981.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

4,354,981.00

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)

6.0 %

12

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person: Percentage calculated based (1) 3,048,037 shares of Common Stock beneficially owned by the reporting person and warrants to acquire 1,306,944 shares of Common Stock beneficially owned by the reporting person, and (2) on 71,410,469 shares of Common Stock outstanding on October 30, 2025, as reported in the Form 10-Q filed by the Issuer for the quarter ended September 30, 2025.

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Xencor Inc
(b)	Address of issuer's principal executive offices: 465 North Halstead Street, Suite 200, Pasadena, CA 91107
Item 2.
(a)	Name of person filing: EcoR1 Capital, LLC, a Delaware limited liability company ("EcoR1") EcoR1 Capital Fund Qualified, L.P., a Delaware limited partnership ("Qualified Fund") Oleg Nodelman Qualified Fund is filing this statement jointly with the other reporting persons, but not as a member of a group, and it expressly disclaims membership in a group. In addition, the filing of this Schedule 13G on behalf of Qualified Fund should not be construed as an admission that it is, and it disclaims that it is, a beneficial owner, as defined in Rule 13d-3 under the Act, of any securities covered by this Schedule 13G. Each reporting person also disclaims beneficial ownership of the securities reported herein except to the extent of that person's pecuniary interest therein.
(b)	Address or principal business office or, if none, residence: 357 Tehama Street #3 San Francisco, CA 94103
(c)	Citizenship: See Item 4 of the cover sheet for each reporting person.
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 98401F105
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: EcoR1: 4,640,000 Oleg Nodelman: 4,640,000 Qualified Fund: 4,354,981
(b)	Percent of class: EcoR1: 6.4% Oleg Nodelman: 6.4% Qualified Fund: 6.0%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: EcoR1: 0 Oleg Nodelman: 0 Qualified Fund: 0
	(ii) Shared power to vote or to direct the vote: EcoR1: 4,640,000 Oleg Nodelman: 4,640,000 Qualified Fund: 4,354,981
	(iii) Sole power to dispose or to direct the disposition of: EcoR1: 0 Oleg Nodelman: 0 Qualified Fund: 0
	(iv) Shared power to dispose or to direct the disposition of: EcoR1: 4,640,000 Oleg Nodelman: 4,640,000 Qualified Fund: 4,354,981
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.
	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.
	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. EcoR1 is the general partner and investment adviser of investment funds, including Qualified Fund. Mr. Nodelman is the control person of EcoR1.
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 acquired and are held in the ordinary course of business and 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. 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.

EcoR1 Capital, LLC

Signature:	/s/ Oleg Nodelman
Name/Title:	Manager
Date:	02/13/2026

Oleg Nodelman

Signature:	/s/ Oleg Nodelman
Name/Title:	Reporting person
Date:	02/13/2026

EcoR1 Capital Fund Qualified, L.P.

Signature:	/s/ Oleg Nodelman
Name/Title:	Manager of the General Partner, EcoR1 Capital, LLC
Date:	02/13/2026

Exhibit Information

EXHIBIT 99.1 - AGREEMENT REGARDING JOINT FILING OF STATEMENT ON SCHEDULE 13D OR 13G

FAQ

What ownership stake in Xencor Inc (XNCR) does EcoR1 Capital report?

EcoR1 Capital reports beneficial ownership of 4,640,000 Xencor common shares, or 6.4% of the outstanding class. This total includes common stock and warrants, based on 71,410,469 shares outstanding as of October 30, 2025, referenced from Xencor’s Form 10‑Q.

How much of Xencor Inc (XNCR) does EcoR1 Capital Fund Qualified, L.P. own?

EcoR1 Capital Fund Qualified, L.P. reports beneficial ownership of 4,354,981 Xencor common shares, representing 6.0% of the class. This figure includes 3,048,037 common shares and warrants to acquire 1,306,944 additional shares, calculated against 71,410,469 shares outstanding as of October 30, 2025.

What is Oleg Nodelman’s reported beneficial ownership in Xencor Inc (XNCR)?

Oleg Nodelman reports beneficial ownership of 4,640,000 Xencor common shares, equal to 6.4% of the outstanding class. His ownership mirrors EcoR1 Capital’s reported stake and is calculated using 71,410,469 shares outstanding as of October 30, 2025, according to Xencor’s Form 10‑Q.

Is EcoR1’s stake in Xencor Inc (XNCR) reported as a passive investment?

Yes, the reporting persons state the Xencor securities were acquired and are held in the ordinary course of business. They certify the holdings were not acquired to change or influence control of Xencor and are not part of any control‑oriented transaction or group arrangement.

How is the percentage ownership in Xencor Inc (XNCR) calculated in this filing?

The reported ownership percentages are calculated using 71,410,469 Xencor common shares outstanding as of October 30, 2025. EcoR1 and Oleg Nodelman each report 6.4%, while EcoR1 Capital Fund Qualified, L.P. reports 6.0%, with totals including both common shares and warrants.