Zenas BioPharma Acquires Exclusive Worldwide Rights To Obexelimab From Xencor

Xencor, Inc., a clinical-stage biopharmaceutical company developing engineered monoclonal antibodies and cytokines for the treatment of cancer and autoimmune diseases, and Zenas BioPharma (“Zenas”), a global biopharmaceutical company based in the USA and China committed to the development and delivery of immune-based therapies, today announced that Zenas has acquired from Xencor exclusive worldwide rights to develop, manufacture and commercialize the investigational antibody obexelimab.

Obexelimab is a potential first-in-class bifunctional antibody that targets CD19 with its variable domain and uses Xencor's XmAb® Immune Inhibitor Fc Domain to target FcγRIIb, a receptor that inhibits the function of B-cells, which are important components in the immune system. Xencor demonstrated through early-stage clinical studies that obexelimab effectively inhibits B-cell function without depleting the cells and generates an encouraging treatment effect in patients with multiple autoimmune diseases.

“Zenas is advancing a broad pipeline of differentiated drug candidates that are intended to bring best-in-class innovation to patients with underserved medical needs,” said Hua Mu, Ph.D., MD, president and chief executive officer at Zenas. “Today, we are pleased to add obexelimab to our portfolio, and based on its clinical profile, we believe it is positioned as a first-in-class candidate with the potential to treat numerous autoimmune diseases.”

“Obexelimab’s highly potent and broad blockade of B-cell activation—without depleting B cells—differentiates it from other B-cell targeting therapies, and it has demonstrated disease-modifying activity in settings where B-cell inhibition is a proven strategy,” said Bassil Dahiyat, Ph.D., president and chief executive officer at Xencor. “In Zenas BioPharma, we have found a partner committed to broadly and aggressively developing therapeutics like obexelimab for patients with autoimmune diseases, enabling Xencor’s continued focus on the growing opportunities provided by our XmAb bispecific antibody and cytokine pipeline.”

Under the terms of the new agreement, Zenas will issue to Xencor a warrant giving Xencor the right to acquire additional Zenas equity, such that Xencor’s total equity in Zenas would be 15% of its fully diluted capitalization following the closing of Zenas’ next round of equity financing, subject to certain requirements. Xencor previously received equity in Zenas under a separate license agreement. Xencor is also eligible to receive up to $480 million based on the achievement of certain clinical development, regulatory and commercialization milestones and is eligible to receive tiered, mid-single digit to mid-teen percent royalties upon commercialization of obexelimab, dependent on geography. Zenas will have sole responsibility for advancing the research, development, regulatory and commercial activities of obexelimab worldwide.