Eli Lilly agreed to acquire Centessa Pharmaceuticals for about $6.3 billion upfront, adding an orexin receptor 2 (OX2R) agonist portfolio aimed at narcolepsy and other sleep-wake disorders. Centessa’s lead asset, cleminorexton (formerly ORX-750), has Phase 2a data across narcolepsy types 1 and 2 and idiopathic hypersomnia, with Lilly positioning the portfolio for broader neuroscience expansion. Separately, Biogen agreed to buy Apellis Pharmaceuticals for about $5.6 billion, accelerating its immunology and rare-disease offerings. The deal brings Biogen commercial assets including Syfovre (pegcetacoplan) for geographic atrophy secondary to age-related macular degeneration and Empaveli for complement-mediated diseases, while expanding internal nephrology expertise. Taken together, the transactions underscore how cash-rich pharma is retooling portfolios around late-stage commercial products and mechanism-led pipelines, with sleep and complement biology both becoming strategic acquisition targets.