Biogen agreed to pay as much as $1 billion to acquire RayThera, a San Diego biotech that has disclosed limited pipeline detail since launching last year. The transaction is structured predominantly around milestone payments, according to the report. The acquisition reflects Biogen’s continued strategy to add early-stage or platform-adjacent assets in inflammation, using milestone-heavy economics to manage upfront risk. For RayThera, the deal provides a route to scale development and potential late-stage funding. Because RayThera’s pipeline has been described as sparse publicly, the key market focus will likely shift to how quickly Biogen can update the specifics of RayThera’s lead programs and clinical plans. For biotech M&A, the reported deal size highlights that large pharma still sees value in buying specialized inflammatory discovery capabilities, even when near-term disclosure is limited.