Xencor Inc

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

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Filed by a Party other than the Registranto

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XENCOR, INC.

(Name of Registrant as Specified in its Charter)

(Name of Person(s) Filing Proxy Statement, if Other Than the Registrant)

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Fellow stockholder,

Xencor applies cutting-edge XmAb® protein engineering technologies to develop better biologic medicines and improve the lives of patients with cancer and other serious diseases. The plug-and-play nature of our XmAb Fc domains and our protein engineering expertise have enabled a broad clinical-stage portfolio of antibody-based drug candidates. We seek to address challenging areas of biology with our drug candidates, testing them in clinical trials to determine which to advance toward registrational studies and which to either partner or terminate. Our future growth is rooted in our commitment to scientific excellence and exploration of therapeutic mechanisms through our exceptional protein engineering expertise.

We are focused on advancing a pipeline of targeted T-cell engaging bispecific antibodies, which we believe hold great potential for the treatment of patients with solid tumors. Recent clinical data updates from T-cell engager programs across multiple tumor types have been highly encouraging and provide rapidly growing validation that they may drive deep and durable clinical responses. In the third quarter of 2023, we began aligning our portfolio to prioritize our T-cell engager programs, which include XmAb819 (ENPP3 x CD3), XmAb808 (B7-H3 x CD28) and XmAb541 (CLDN6 x CD3). We have also narrowed the clinical development plan for our dual checkpoint inhibitor, vudalimab (PD-1 x CTLA-4), in treating patients with advanced prostate and non-small lung cell cancers. We recently presented early Phase 2 data indicating that vudalimab monotherapy has been associated with clinical response in 5 of 12 evaluable patients with an advanced form of prostate cancer, and its safety profile has been consistent with other checkpoint inhibitor therapies. Finally, in the first half of 2024, we plan to conclude Phase 1 studies evaluating our XmAb564 and XmAb662 engineered cytokines and pause further development of both programs, pending review of data emerging from competitive programs.

The inherent modular nature of XmAb technologies and our many collaborations and licensing agreements expand our reach. Several partners are developing their own XmAb drug candidates, which generate revenue streams that have enabled our strong financial foundation. Along with our partners, more than 20 XmAb drug candidates are in clinical testing, and multiple XmAb medicines are marketed by partners. In November 2023, we monetized portions of financial interests on sales of two marketed XmAb medicines for $215.0 million. Proceeds from the monetization provide us near-term flexibility to focus resources on what we believe to be our biggest value drivers and enhance our pipeline with novel XmAb drug candidates.

We appreciate your perspective. You are invited and most welcome to join us at our 2024 Annual Meeting of Stockholders on Thursday, June 13, 2024 at 1:30 p.m. PT at our laboratories and headquarters in Pasadena, California. As always, please reach out to our investor relations personnel to help increase your understanding of our business strategy and corporate governance practices.

Bassil I. Dahiyat, Ph.D.

President, Chief Executive Officer and Director

XENCOR, INC.

465 North Halstead Street, Suite 200

Pasadena, CA 91107

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

To Be Held On June 13, 2024

Dear Stockholder:

You are cordially invited to attend the 2024 Annual Meeting of Stockholders of Xencor, Inc., a Delaware corporation (the “Company”) to be held on Thursday, June 13, 2024 at 1:30 p.m. Pacific Time at the Company’s headquarters, 465 North Halstead Street, Suite 200, Pasadena, California 91107. We are holding the meeting for the following purposes:

1. To elect the eight nominees to the Board of Directors named in the accompanying Proxy Statement to serve until the next annual meeting and until their successors are duly elected and qualified;

2. To ratify the selection by the Audit Committee of the Board of Directors of RSM US LLP as the independent registered public accounting firm of the Company for its fiscal year ending December 31, 2024;

3. To approve, by non-binding advisory vote, the compensation of the Company’s named executive officers, as disclosed in the accompanying Proxy Statement; and

4. To conduct any other business properly brought before the meeting or any adjournments or postponements thereof.

These items of business are more fully described in the Proxy Statement accompanying this Notice (the “Proxy Statement”).

The record date for the annual meeting is April 15, 2024. Only stockholders of record at the close of business on that date may vote at the meeting or any adjournment thereof.

Our Board of Directors recommends that you vote FOR the election of each of the director nominees and FOR Proposals 2 and 3.

If we decide to make any change in the date, time or location, or to hold the annual meeting virtually by remote communication, an announcement of such changes will be made through a press release that will also be filed with the Securities and Exchange Commission as additional proxy materials and we will post details on our website athttps://investors.xencor.com. Please check our website in advance of the date of the annual meeting if you are planning to attend in person. If we elect to hold a virtual meeting, this will not have any impact on your ability to vote by proxy using the enclosed proxy card, vote by proxy on the internet or vote by proxy over the telephone, each as explained in this Proxy Statement. As always, we encourage you to vote your shares prior to the annual meeting.

April 24, 2024

You are cordially invited to attend the annual meeting. Whether or not you expect to attend the meeting, please complete, date, sign and return the proxy mailed to you as promptly as possible in order to ensure your representation at the meeting. Even if you have voted by proxy, you may still vote if you attend the meeting. Please note, however, that if your shares are held of record by a broker, bank or other nominee and you wish to vote at the meeting, you must obtain a proxy issued in your name from that record holder.

Important Notice Regarding the Availability of Proxy Materials for the Stockholders Meeting to Be Held on June 13, 2024: Our Notice of Annual Meeting of Stockholders, Proxy Statement and Annual Report on Form 10-K for the fiscal year ended December 31, 2023 will be available at www.proxydocs.com/XNCR.

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