Lilly and Rigel Partner on RIPK1 Inhibitors

Pursuant to the collaboration, Lilly will also lead all clinical development of brain penetrating RIPK1 inhibitors in central nervous system (CNS) diseases. Under the terms of the agreement, Lilly will pay an upfront cash payment to Rigel of $125 million. Rigel may also be eligible to receive up to $835 million in potential development, regulatory, and commercial milestone payments, as well as tiered royalties ranging from the mid-single digit to high-teens that will vary depending upon Rigel's clinical development investment. Lilly and Rigel will co-develop R 552 at specified contribution levels. Lilly will be responsible for all costs of global commercialization for R 552, and Rigel will have the right to co-commercialize R 552 in the U.S. Lilly will be solely responsible for all clinical development and commercialization of brain penetrating RIPK1 inhibitors in CNS indications.

RIPK1 is a critical signaling protein implicated in a broad range of key inflammatory cellular processes including necroptosis, a type of regulated cell death, and cytokine production. In necroptosis, cells rupture leading to the dispersion of cell contents which can trigger an immune response and enhance inflammation. Inhibiting RIPK1 may be a new approach to treating various autoimmune, inflammatory, and neurodegenerative disorders. In pre-clinical studies, Rigel's R 552 demonstrated prevention of joint and skin inflammation in a RIPK1-mediated murine model of inflammation and tissue damage..