Gilead and Xilio Announce Exclusive License Agreement for Tumor-Activated IL-12 Program

Gilead Sciences, Inc. (Nasdaq: GILD) and Xilio Therapeutics, Inc. (Nasdaq: XLO) today announced an exclusive license agreement to develop and commercialize Xilio’s Phase 1 tumor-activated IL-12 program, XTX301.

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Xilio Therapeutics is a clinical-stage biotechnology company discovering and developing tumor-activated immuno-oncology therapies. The company is using its proprietary tumor-activation platform to build a pipeline of novel, tumor-activated molecules, including antibodies, cytokines, bispecifics, and cell engagers, which are designed to optimize the therapeutic index and localize anti-tumor activity within the tumor microenvironment. XTX301 is currently being evaluated in a Phase 1 dose escalation trial in patients with advanced solid tumors.

“Xilio’s novel tumor-activation platform naturally complements Gilead’s clinical development program in difficult-to-treat cancers and expands our focus in immuno-oncology,” said Bill Grossman, MD, PhD, Senior Vice President, Oncology Clinical Development, Gilead Sciences. “We believe IL-12 has the potential to treat a broad range of tumor types and are excited to partner with Xilio to advance XTX301, a tumor-activated IL-12, as a monotherapy and a combination therapy across a variety of solid tumors.”

“Gilead’s confidence in our tumor-activated technology, combined with their deep expertise in developing and commercializing novel immuno-oncology products, will enable us to accelerate and expand the development of XTX301, our tumor-activated IL-12,” said René Russo, Pharm.D., President and Chief Executive Officer of Xilio. “We look forward to collaborating with Gilead as we seek to deliver on the potential for XTX301 to provide a meaningful benefit for a range of tumor types, including immunologically cold tumors, while overcoming the severe toxicities historically associated with IL-12.”

Terms of the Agreement

Under the terms of the agreement, Xilio granted Gilead an exclusive global license to develop and commercialize XTX301, Xilio’s tumor-activated IL-12. Xilio will receive $43.5 million in upfront payments, including a cash payment of $30 million and an initial equity investment by Gilead of $13.5 million in Xilio common stock at a premium. Xilio will be eligible to receive up to $604 million in additional contingent payments, including additional equity investments by Gilead, a transition fee and specified development, regulatory and sales-based milestones. Xilio will also be eligible to receive tiered royalties ranging from high single digits to mid-teens on annual global net product sales.