Arrowhead Pharmaceuticals Receives FDA Breakthrough Therapy Designation for Plozasiran Page 1

Arrowhead Pharmaceuticals, Inc. (NASDAQ: ARWR) today announced that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy designation to investigational plozasiran as an adjunct to diet to lower triglycerides in adults with familial chylomicronemia syndrome (FCS), a serious and rare genetic disorder characterized by extremely high triglyceride levels that can cause acute and potentially fatal pancreatitis. There are currently no approved treatments in the U.S. for FCS.

“There are currently no FDA-approved therapies to specifically treat FCS, leaving physicians with few options to help their patients,” said Chris Anzalone, Ph.D., President and CEO of Arrowhead. “Results from clinical studies of investigational plozasiran have been very encouraging and supportive of further development and commercialization in multiple patient populations. Receiving FDA Breakthrough Therapy designation for plozasiran provides important benefits and the opportunity to accelerate the process of delivering plozasiran to the patients who need it.”