Seattle-based Chinook has two late-stage drugs in development to treat Immunoglobulin A Nephropathy (IgAN), a rare and progressive kidney disease that mostly affects young adults and currently lacks targeted treatment options.

The therapies are atrasentan, an oral endothelin A receptor antagonist (ERA) and zigakibart, a monoclonal antibody. Atrasentan is currently in Phase 3 development for IgAN and has shown significant reductions in proteinuria. Atrasentan is also in early-stage development for other rare kidney diseases. A phase 3 trial for zigakibart in IgAN started in July 2023.

“We are excited to complete this important transaction and look forward to leveraging our combined resources and expertise to further advance the development of these promising treatments for the benefit of patients with rare, severe chronic kidney diseases,” said Novartis CEO Vas Narasimhan.

Novartis said that Chinook stockholders will receive $40.00 in cash per Chinook share (totaling $3.2 billion), and up to an additional $4.00 in cash per Chinook share, through a contingent value right (CVR) if certain regulatory milestones are achieved, representing a potential additional $300 million in aggregate contingent consideration.