On October 14, 2025 Xencor, Inc. (NASDAQ:XNCR), a clinical-stage biopharmaceutical company developing engineered antibodies for the treatment of cancer and autoimmune diseases, reported 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 (Free AACR Whitepaper)-NCI-EORTC Conference on Molecular Targets and Cancer Therapeutics, being held October 22-26, 2025 in Boston, Massachusetts.

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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.

(Press release, Xencor, OCT 14, 2025, View Source [SID1234656648])