Dose-dependent Clinical Activity Reported from Ph 1 Trial of LYL797

“We are encouraged to see clinical responses and a clear dose-dependent indication of antitumor clinical activity from treatment with LYL797 in patients with advanced triple-negative breast cancer,” said Lynn Seely, MD, President and Chief Executive Officer of Lyell. “Our translational data provide, to our knowledge, the first demonstration of persistent CAR T cell infiltration into solid tumors associated with evidence of cancer cell killing. This early validation of our anti-exhaustion technology gives us the conviction to expand our trial to include patients with ROR1+ ovarian or endometrial cancers, while continuing to enroll patients with triple-negative breast or non-small lung cancers, and also to initiate a new clinical trial for patients with multiple myeloma and chronic lymphocytic leukemia. This compelling early clinical data from LYL797 gives us a high degree of confidence to advance LYL119, our next generation ROR1-targeted product candidate with even more powerful anti-exhaustion technology. We have submitted an IND for LYL119 and expect to enter the clinic this year.”