MONROVIA, CA, USA I January 08, 2020 I Xencor, Inc. (NASDAQ:XNCR), a clinical-stage biopharmaceutical company developing engineered monoclonal antibodies for the treatment of cancer, autoimmune disease, asthma and allergic diseases, today announced it has entered into a technology license agreement in which Gilead Sciences, Inc., will access Xencor’s Xtend™ extended half-life and Cytotoxic XmAb® Fc technologies for developing and commercializing GS-9722, Gilead’s first-in-class effector-enhanced broadly neutralizing anti-HIV antibody, which is currently in Phase 1 clinical development.

“Xencor’s plug-and-play antibody engineering platform enables selective licensing of our Fc domain technologies to partners to improve drug candidate properties in their own antibody development programs,” said Bassil Dahiyat, Ph.D., president and chief executive officer at Xencor. “This agreement with Gilead expands the potential of XmAb technologies to create new therapies for people living with HIV.”

Under the terms of the agreement, Xencor has granted Gilead an exclusive license for GS-9722 and up to three additional anti-HIV antibodies. Xencor retains the right to grant licenses for other antibodies directed to the target. Gilead will be solely responsible for the activities and costs related to research, development, regulatory and commercial activities. Xencor will receive an upfront payment and is eligible to receive milestones and royalties for the successful development and commercialization of these products.

About Xtend™ XmAb® Fc Technology

Xencor’s Xtend™ XmAb® Fc domains increase circulating half-life by increasing binding affinity to the receptor FcRn. FcRn is present inside lysosomes in endothelial cells lining the blood vessels and functions to rescue antibodies from the degradation that makes most proteins short-lived in circulation. Half-life extension can be exploited to potentially improve therapeutic antibody performance in several ways, such as increasing dosing interval or decreasing drug quantities at the same dosing interval compared to a parent antibody. Xtend technology is currently in multiple clinical-stage programs and one approved therapy, Alexion’s Ultomiris® (ravulizumab-cwvz).

About Cytotoxic XmAb® Fc Technology

Xencor’s Cytotoxic XmAb® Fc domain is designed to improve the immune system’s elimination of tumor and other pathologic cells by antibody-dependent cellular cytotoxicity (ADCC). The Cytotoxic Fc domain is engineered to increase binding affinity to activating Fcγ receptors to enhance activation of natural killer (NK) cells and other immune cells such as macrophages, which play a role in immunity by engulfing and digesting foreign material.

About Xencor, Inc.

Xencor is a clinical-stage biopharmaceutical company developing engineered monoclonal antibodies for the treatment of cancer, autoimmune diseases, asthma and allergic diseases. Currently, 15 candidates engineered with Xencor’s XmAb® technology are in clinical development internally and with partners. Xencor’s XmAb antibody engineering technology enables small changes to the structure of monoclonal antibodies resulting in new mechanisms of therapeutic action. For more information, please visit

SOURCE: Xencor