Instil Bio, Inc. announced that the first patient has been dosed in a Phase 1 dose escalation study of ITIL-306 (NCT05397093) for the treatment of multiple solid tumors. ITIL-306 is Instil's first genetically-engineered Costimulatory Antigen Receptor-TIL (CoStAR-TIL) therapy. Instil's first-in-human Phase 1 study of ITIL-306 is an open-label, multicenter study in patients with non-small cell lung cancer, ovarian cancer, and renal cell carcinoma.

Patients in the first dose cohort will receive a target dose of one billion CoStAR-transduced TILs after receiving a reduced intensity lymphodepletion regimen and no post-infusion interleukin-2. The study will evaluate safety of ITIL-306 in addition to efficacy and translational endpoints. The company anticipates reporting initial clinical data from the Phase 1 trial in 2023. ITIL-306 is an autologous TIL cell therapy engineered with a novel and proprietary CoStAR molecule that is activated by folate receptor alpha (FRa) to provide robust costimulatory signals within the tumor microenvironment.

CoStAR builds on the key advantages of native TILs to enhance the cytokine release, cytolytic activity, and proliferation of TILs in the tumor microenvironment. Previously published preclinical data demonstrates the ability of CoStAR-T cells to enhance tumor control in vivo in the absence of exogenous IL-2, supporting a treatment regimen free of IL-2 in the Phase 1 study of ITIL-306.