On Mar. 27, 2025, Eli Lilly and SiteOne Therapeutics, a private biotechnology company developing small molecule inhibitors of sodium channels to treat pain and other neuronal hyperexcitability disorders, announced a definitive agreement for Lilly to acquire SiteOne.

The transaction includes STC-004, a Phase 2 ready Nav1.8 inhibitor being studied for the treatment of pain. STC-004 may represent a next-generation, non-opioid treatment for patients suffering from chronic pain.

Under the terms of the agreement, Lilly will acquire SiteOne and SiteOne shareholders could receive up to $1.0 billion in cash, inclusive of an upfront payment and subsequent payments upon achievement of certain regulatory and commercial milestones.