Ionis drops as Arrowhead posts late-stage trial win for lipid-lowering drug

Arrowhead Pharmaceuticals (ARWR) on Wednesday announced a late-stage trial win for its lipid-lowering agent plozasiran in patients with severe hypertriglyceridemia, hurting the shares of Ionis Pharmaceuticals (IONS), which is advancing a rival therapy.

California-based Arrowhead (ARWR) said that plozasiran, which is already available in the U.S. as Redemplo for familial chylomicronemia syndrome, the most serious form of sHTG, met all the key goals in its Phase 3 SHASTA-3 and SHASTA-4 trials. 

Its shares added 18% in reaction, while Ionis (IONS), whose sHTG therapy olezarsen is currently under the FDA's priority review with a decision expected by June 30, lost nearly 5%.

Arrowhead (ARWR) said that plozasiran, as a subcutaneous injection, met the primary endpoint and all prespecified secondary endpoints in SHASTA-3 and SHASTA-4, causing median triglyceride reductions of 79% and 81% at month 12, respectively.

In comparison, patients on placebo witnessed a median triglyceride reduction of roughly 27%. There were no new safety events, and the incidence of overall treatment-emergent adverse events and related TEAEs was in line with plozasiran’s prior study data.

The company expects to submit a supplemental new drug application with the FDA before the end of this year, seeking a label expansion for the drug in the U.S. for sHTG.