With a successful phase III study of plozasiran in hand, Arrowhead Pharmaceuticals Inc. plans to file an NDA with the U.S. FDA for treating the rare genetic disease familial chylomicronemia syndrome. While the data are strong, the company is playing catch-up to Ionis Pharmaceuticals Inc., which has a December 2024 PDUFA for its candidate, olezarsen, in the same indication.