Xencor Announces Presentation of Initial Phase 1 Dose-Escalation Results of XmAb819 in Clear Cell Renal Cell Carcinoma at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics

Audio By Carbonatix

PASADENA, Calif.--(BUSINESS WIRE)--Oct 14, 2025--

Xencor, Inc. (NASDAQ:XNCR), a clinical-stage biopharmaceutical company developing engineered antibodies for the treatment of cancer and autoimmune diseases, today announced the upcoming presentation of initial results from the ongoing Phase 1 dose-escalation study of XmAb819, a bispecific ENPP3 x CD3 T-cell engaging bispecific antibody, in patients with clear cell renal cell carcinoma (ccRCC) in a poster at the AACR-NCI-EORTC Conference on Molecular Targets and Cancer Therapeutics, being held October 22-26, 2025 in Boston, Massachusetts.

Today, Xencor management also became aware that an investment bank published takeaways from the abstract accepted for presentation at the conference, which is not publicly available via the conference website or app. Full abstracts are scheduled to be released by the conference next Wednesday, October 22 at 12 p.m. ET.

Xencor submitted a placeholder abstract with limited detail based on a previous data-cut from the ongoing dose-escalation study of XmAb819 (Clinicaltrials.gov Identifier: NCT05433142). The abstract contained a high-level safety summary across all dosing cohorts with no additional information regarding efficacy beyond what had been previously disclosed during a public webcast in September 2024.

Presentation of a dataset from an updated data-cut at the conference will include a detailed safety analysis along with efficacy results from the target dose range when the embargo lifts. Management will also host a webcast and conference call to discuss the results and will provide access credentials for the event on a later date.

Presentation Details

• Title: Preliminary Phase 1 safety and antitumor activity of XmAb819, a first-in-class ENPP3 x CD3 bispecific antibody, in patients with advanced clear cell renal cell carcinoma (ccRCC)
• Session: Poster Session B
• Date and Time: Friday, October 24, 2025 from 12:30-4:00 p.m. ET

About XmAb819

XmAb819 is a first-in-class, tumor-targeted, T-cell engaging XmAb 2+1 bispecific antibody in development for patients with clear cell renal cell carcinoma (ccRCC). XmAb819 engages the immune system and activates T cells for highly potent and targeted lysis of tumor cells expressing ENPP3, an antigen highly expressed on kidney cancers. ENPP3 is a differentially expressed target, with high level expression in renal cell carcinoma (RCC) and low-level expression on normal tissues. With two tumor-antigen binding domains and one T-cell binding domain, Xencor’s XmAb 2+1 format enables antibodies to bind more avidly and selectively kill tumor cells with higher antigen density, potentially sparing normal cells. Xencor is conducting a Phase 1 study to evaluate XmAb819 in patients with advanced ccRCC.

About Xencor

Xencor is a clinical-stage biopharmaceutical company developing engineered antibodies for the treatment of patients with cancer and autoimmune diseases. More than 20 candidates engineered with Xencor's XmAb® technology are in clinical development, and multiple XmAb medicines are marketed by partners. Xencor's XmAb engineering technology enables small changes to a protein’s structure that result in new mechanisms of therapeutic action. For more information, please visit www.xencor.com.

Forward-Looking Statements

Certain statements contained in this press release may constitute forward-looking statements within the meaning of applicable securities laws. Forward-looking statements include statements that are not purely statements of historical fact, and can generally be identified by the use of words such as “potential,” “can,” “will,” “plan,” “may,” “could,” “would,” “expect,” “anticipate,” “seek,” “look forward,” “believe,” “committed,” “investigational,” “indicates,” “supports,” and similar terms, or by express or implied discussions relating to Xencor’s business, including, but not limited to, statements regarding expectations for clinical progress, planned presentations of clinical data, planned and in process clinical trials, and other statements that are not purely statements of historical fact. Such statements are made on the basis of the current beliefs, expectations, and assumptions of the management of Xencor and are subject to significant known and unknown risks, uncertainties and other factors that may cause actual results, performance or achievements and the timing of events to be materially different from those implied by such statements, and therefore these statements should not be read as guarantees of future performance or results. Such risks include, without limitation, the risks associated with the process of discovering, developing, manufacturing and commercializing drugs that are safe and effective for use as human therapeutics and other risks, including the ability of publicly disclosed preliminary clinical trial data to support continued clinical development and regulatory approval for specific treatments and the risks, uncertainties and other factors described under the heading “Risk Factors” in Xencor's annual report on Form 10-K for the year ended December 31, 2024 as well as Xencor's subsequent filings with the Securities and Exchange Commission. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. This caution is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, as amended to date. All forward-looking statements are qualified in their entirety by this cautionary statement and Xencor undertakes no obligation to revise or update these forward-looking statements to reflect events or circumstances after the date hereof, except as required by law.

View source version on businesswire.com:https://www.businesswire.com/news/home/20251014017914/en/

CONTACT: Charles Liles

[email protected]

(626) 737-8118

KEYWORD: UNITED STATES NORTH AMERICA CALIFORNIA MASSACHUSETTS

INDUSTRY KEYWORD: BIOTECHNOLOGY HEALTH PHARMACEUTICAL CLINICAL TRIALS ONCOLOGY

SOURCE: Xencor, Inc.

Copyright Business Wire 2025.

PUB: 10/14/2025 12:45 PM/DISC: 10/14/2025 12:44 PM

http://www.businesswire.com/news/home/20251014017914/en