Ropes & Gray Advises Xilio Therapeutics in Gilead Sciences Exclusive Global License Agreement Up to $647.5 Million

Ropes & Gray represented Xilio Therapeutics, Inc., in an exclusive global license agreement with Gilead Sciences to develop and commercialize Xilio’s tumor-activated IL-12 program, XTX301. The transaction was announced on March 28.

Xilio Therapeutics 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 localize anti-tumor activity within the tumor microenvironment. XTX301 is currently being evaluated in a Phase 1 trial in patients with advanced solid tumors. XTX301 has the potential to work in cold tumors, those that do not trigger strong immune responses, making them unresponsive to current immunotherapy treatments. Xilio will be responsible for XTX301’s ongoing Phase 1 study through the dose-escalation phase, after which Gilead can elect to take over development and commercialization.

Under the agreement, 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.

The Ropes & Gray team was led by life sciences licensing partner Hannah England and life sciences licensing senior attorney Ian Longacre.