Xencor Doses First Subject in Phase 1/2 Study of XmAb®942 in Development for Patients with Inflammatory Bowel Disease

Xencor, Inc. (NASDAQ: XNCR), a clinical-stage biopharmaceutical company developing engineered antibodies for the treatment of cancer and other serious diseases, today announced that it has initiated dosing of healthy volunteers in the first-in-human study of XmAb^®942, an investigational high-potency extended half-life anti-TL1A antibody. Xencor continues to expect initial data from the ongoing study during the first half of 2025.

"An anti-TL1A antibody engineered for improved target coverage with long duration of action could transform the clinician’s therapeutic toolbox in inflammatory bowel disease,” said Kenneth Hung, M.D., Ph.D., senior vice president, clinical development at Xencor. "We are excited to announce this first dosing of XmAb942 in healthy participants and believe that XmAb942’s properties, including potentially class-leading potency, may result in a therapeutic option with improved clinical benefit and a more convenient dosing regimen than other anti-TL1A antibodies currently in clinical development.”

The Phase 1/2 randomized, double-blind, placebo-controlled study of XmAb942 will be conducted in three parts. In Phase 1, Part A will enroll healthy volunteers into single-ascending dose (SAD) cohorts, and additional healthy volunteers would receive repeat doses in Part B. In Phase 2, Part C will enroll patients with ulcerative colitis who would receive the dosing determined from Parts A and B. (ClinicalTrials.gov Identifier: NCT06619990)

Xencor’s poster with preclinical characterization of XmAb942 was presented at the United Europe Gastroenterology Week (UEGW) in October 2024. The poster is archived under the "Publications” and the "Events & Presentations" pages of the Company's website located at www.xencor.com.

About XmAb^®942

XmAb^®942 is a high-potency, extended half-life, investigational anti-TL1A antibody in development for patients with inflammatory bowel disease, such as ulcerative colitis (UC) and Crohn’s disease (CD). The first generation of anti-TL1A antibodies, designed to block the interaction between the death receptor 3 (DR3) receptor and its ligand tumor necrosis factor (TNF)-like cytokine 1A (TL1A), have reduced disease activity in patients with UC and CD in multiple clinical studies. XmAb942’s half-life is enabled by Xencor’s validated Xtend™ Fc domain and could potentially support an eight- to twelve-week dosing interval in humans. Xencor initiated a Phase 1 dose-escalation study of XmAb942 in healthy volunteers in the fourth quarter of 2024.

About Xencor

Xencor is a clinical-stage biopharmaceutical company developing engineered antibodies for the treatment of patients with cancer and other serious 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

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