Eli Lilly agreed to acquire Centessa Pharmaceuticals for up to $7.8 billion, paying $38 per share plus contingent value rights tied to clinical approvals, to expand its neuroscience pipeline. Centessa’s orexin receptor 2 (OX2R) agonist cleminorexton (formerly ORX-750) has generated phase IIa results in narcolepsy types 1 and 2 and idiopathic hypersomnia, adding to Lilly’s push beyond obesity. In parallel, Biogen agreed to purchase Apellis Pharmaceuticals for about $5.6 billion to build out immunology and rare-disease offerings. The deals place both companies behind clinical-stage or commercial assets linked to immune signaling—sleep-wake regulation for Lilly via OX2R biology, and complement inhibition for Biogen through Apellis’ marketed portfolio. These transactions underscore how large pharma is prioritizing platform-like biology and repeatable drug classes, even as exclusivity cliffs loom. For investors and R&D leaders, the key near-term reads are execution on pivotal trial plans and regulatory milestones that determine deal value.