Vertex Pharmaceuticals reported positive Phase III Rainier data for povetacicept, its dual BAFF/APRIL inhibitor acquired in a takeover, and is preparing a biologics license application intended for accelerated review. Interim results showed a large, placebo‑adjusted reduction in proteinuria—analysts called it one of the strongest Phase III responses in IgAN to date. Vertex said it will complete the BLA imminently and pursue U.S. approval; the program positions the company squarely in a crowded IgAN race alongside Otsuka and Vera Therapeutics. Regulators have previously used proteinuria reductions as a surrogate for accelerated pathways in kidney disease, a context Vertex and market watchers invoked in assessing commercial potential.