Novo Nordisk agreed to acquire global rights to Omeros’ MASP‑3 antibody zaltenibart in a deal worth up to $2.1 billion, with near-term payments and royalties. Novo said it will launch Phase 3 testing in paroxysmal nocturnal hemoglobinuria (PNH) and explore additional rare blood and kidney disorders. Omeros retains development continuity but stands to collect substantial milestones. Zaltenibart targets MASP‑3, a protease in the complement lectin pathway; blocking MASP‑3 may reduce complement‑mediated hemolysis both intra‑ and extravascularly, a mechanism that could differentiate it from existing complement inhibitors. The agreement signals large pharma appetite for complement biology and rare-disease franchises.