Fulcrum Therapeutics said it is axing most roles and discontinuing development of its sickle cell disease candidate following FDA concerns about the benefit-risk profile. The company reported that 48 of 57 employees will be let go, leaving nine full-time staff as it reduces expenses and seeks strategic alternatives. Fulcrum tied the decision to concerns about an unexpectedly high rate of secondary hematologic malignancies observed in patients treated with Ipsen’s Tazverik (tazemetostat), a PRC2 inhibitor with a related mechanism. Fulcrum said the FDA concluded that pharmacological intervention targeting the PRC2 complex carries equivalent malignancy risk, leaving no viable regulatory path forward. The abrupt pivot highlights how mechanistic class effects and safety signals from other marketed programs can quickly reshape development strategies for early-to-mid stage biotechs.