Prothena Corporation plc (NASDAQ:PRTA) released data from the Phase 3 AFFIRM-AL clinical trial evaluating birtamimab in patients with AL amyloidosis on Friday. AL (amyloid light-chain) amyloidosis is a systemic disease where abnormal proteins, called amyloid fibrils, accumulate in various organs. It’s the most common type of systemic amyloidosis. The Phase 3 AFFIRM-AL trial enrolled 207 newly diagnosed patients. Birtamimab was given to the active arm every 28 days at a dose level of 24 mg/kg (ma