Pharmaceutical company Arrowhead Pharmaceuticals Inc (NASDAQ: ARWR) reported positive topline results from its Phase 3 SHASTA-3 and SHASTA-4 studies of plozasiran in patients with severe hypertriglyceridaemia, with both trials meeting their primary endpoint of triglyceride reduction and all prespecified secondary endpoints, including a statistically significant reduction in acute pancreatitis compared with placebo.

Patients receiving 25mg plozasiran every three months achieved median triglyceride reductions of 79% in SHASTA-3 and 81% in SHASTA-4 at 12 months. A pooled analysis showed a 78% reduction in acute pancreatitis events across the overall study population and a 100% reduction among patients at the highest risk of the condition.

Plozasiran demonstrated a safety and tolerability profile consistent with previous studies, with no new safety signals reported. Arrowhead plans to use data from the SHASTA-3, SHASTA-4 and MUIR-3 studies to seek regulatory approval for severe hypertriglyceridaemia, beginning with a planned supplemental new drug application to the U.S. Food and Drug Administration before the end of 2026.

Detailed results will be presented at the European Society of Cardiology Congress on 30 August 2026.