NEW YORK – Gilead Sciences and Xilio Therapeutics on Thursday announced a licensing deal for Xilio's IL-12 molecule, XTX301.
Xilio has been evaluating the tumor-activated IL-12 molecule in a Phase I clinical trial in patients with advanced solid tumors that have failed standard therapy. In the trial's second part, Part Ib, Xilio is limiting enrollment to patients with advanced melanoma, non-small cell lung cancer, head and neck squamous cell carcinoma, triple-negative breast cancer, microsatellite instability (MSI)-high or DNA mismatch repair deficient (dMMR) colorectal cancer, T-cell lymphoma, MSI-high or dMMR endometrial cancer, prostate cancer, ovarian cancer, pancreatic cancer, and microsatellite stable colorectal cancer. Patients must be able to provide fresh tumor biopsies before and after treatment.
Waltham, Massachusetts-based Xilio believes that XTX301 can stimulate patients' anti-tumor immunity and reprogram their tumor microenvironments from "cold" to "hot."
Under the terms of the agreement, Gilead is acquiring exclusive global licensing rights to develop and commercialize XTX301. In exchange, Gilead is paying $43.5 million to Xilio upfront, including a cash payment of $30 million and a $13.5 million equity investment in Xilio common stock at a premium.
Xilio will also be eligible for $604 million in additional equity investments, a transaction fee, and development, regulatory, and sales-based milestones. Should XTX301 make it to market, Gilead will pay Xilio tiered royalties on net sales ranging from high-single-digit to mid-teen amounts.
Xilio will continue to conduct the ongoing XTX301 clinical trial through its dose-expansion phase. After Xilio delivers a clinical data package, Gilead can then choose to take on responsibilities for developing and commercializing the agent for a $75 million transition fee. Before that transition fee, Xilio can receive up to a total of $29 million in additional equity investments and a development milestone payment from Gilead.
"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," Xilio President and CEO René Russo said in a statement.