Eli Lilly agreed to acquire Centessa Pharmaceuticals in a $6.3 billion transaction, betting its orexin receptor 2 (OX2R) agonist pipeline can expand neuroscience growth beyond Lilly’s obesity cash flow. Centessa’s cleminorexton showed positive phase 2 results across narcolepsy types and idiopathic hypersomnia, and the deal adds additional clinical-stage and preclinical OX2R assets. At the same time, Biogen agreed to buy Apellis Pharmaceuticals for roughly $5.6 billion, adding commercial immune-related drugs pegcetacoplan (Empaveli) and Syfovre to its portfolio. The acquisition is expected to strengthen Biogen’s ability to launch and expand immunology and rare-disease programs, including its pipeline effort for felzartamab. Together, the transactions underscore how large pharma is using blockbuster-generated cash and manufacturing scale to buy near-term revenue and later-stage clinical options across CNS and immune pathways.