Biogen agreed to acquire RayThera in a backloaded deal valued up to $1 billion, aiming to add preclinical immunology assets to its pipeline. The companies said the transaction would bring anti-inflammatory candidates to Biogen, led by a development prospect approaching clinical entry. The structure emphasized milestone-driven payments, aligning risk-sharing with the technical progress of RayThera’s programs. Biogen’s move follows the broader pattern of large pharma replenishing immunology and inflammation portfolios with earlier-stage targets. For RayThera, the deal provides resources to advance preclinical candidates through IND-enabling work and early clinical testing, while Biogen gains a portfolio designed to target inflammatory pathways across disease categories.