— Gilead Granted Exclusive License to Xilio’s Tumor-Activated IL-12 Program, Including XTX301, a Clinical-Stage IL-12 Molecule with Potential to Treat a Broad Range of Cancers —

FOSTER CITY, CA & WALTHAM, MA, USA I March 28, 2024 I 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.

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.

Xilio will be responsible for conducting clinical development of XTX301 in the ongoing Phase 1 clinical trial through dose expansion. Following the delivery by Xilio of a specified clinical data package for XTX301, Gilead can elect to transition responsibilities for the development and commercialization of XTX301 to Gilead, subject to the terms of the agreement and payment by Gilead of a $75 million transition fee. Prior to the potential transition fee, Xilio is eligible to receive up to a total of $29 million in additional equity investments and a development milestone payment.

Gilead does not exclude acquired IPR&D expenses from its non-GAAP financial measures. This transaction is expected to reduce Gilead’s GAAP and non-GAAP 2024 EPS by approximately $0.03 – $0.04.

About XTX301 (IL-12) and the Phase 1 Clinical Trial

XTX301 is an investigational tumor-activated IL-12 designed to potently stimulate anti-tumor immunity and reprogram the tumor microenvironment (TME) of poorly immunogenic “cold” tumors towards an inflamed or “hot” state. Xilio is currently evaluating the safety and tolerability of XTX301 as a monotherapy in patients with advanced solid tumors in a first-in-human, multi-center, open-label Phase 1 clinical trial. Please refer to NCT05684965 on www.clinicaltrials.gov for additional details.

About Xilio Therapeutics

Xilio Therapeutics is a clinical-stage biotechnology company discovering and developing tumor-activated immuno-oncology (I-O) therapies with the goal of significantly improving outcomes for people living with cancer without the systemic side effects of current I-O treatments. The company is using its proprietary 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. Xilio is currently advancing multiple programs for tumor-activated I-O treatments in clinical development, as well as leveraging its differentiated research platform to advance tumor-activated bispecific and cell engager molecules in preclinical development. Learn more by visiting www.xiliotx.com and follow us on LinkedIn (Xilio Therapeutics, Inc.).

About Gilead Sciences

Gilead Sciences, Inc. is a biopharmaceutical company that has pursued and achieved breakthroughs in medicine for more than three decades, with the goal of creating a healthier world for all people. The company is committed to advancing innovative medicines to prevent and treat life-threatening diseases, including HIV, viral hepatitis, COVID-19, and cancer. Gilead operates in more than 35 countries worldwide, with headquarters in Foster City, California.

SOURCE: Gilead Sciences