Eli Lilly is ending its collaboration with Foghorn Therapeutics in synthetic lethality, according to the latest reporting that the biotech has cut headcount by 40% after the partnership was culled over disappointing early data. The companies are dropping their Phase 1 synthetic lethality drug development efforts, and Foghorn’s restructuring reflects a broader pattern of selective portfolio trimming as investors and pharma push harder for early clinical signals. For the sector, the decision underscores the risk profile of early synthetic lethality strategies and the increasing scrutiny applied to whether mechanistic programs translate into reproducible human biology.