Arrowhead Pharmaceuticals Phase 3 Clinical Results for Plozasiran in Severe Hypertriglyceridemia
Arrowhead Pharmaceuticals Inc. presented Phase 3 data for plozasiran (marketed as REDEMPLO) in severe hypertriglyceridemia (sHTG) at the European Society of Cardiology Congress 2026 in Munich. The two double‑blind, placebo‑controlled studies, SHASTA‑3 and SHASTA‑4, enrolled a total of 757 patients who received subcutaneous plozasiran 25 mg or matching placebo once every three months.
At month 12, plozasiran reduced triglyceride levels by 79 % in SHASTA‑3 and by 81 % in SHASTA‑4 versus placebo. More than 90 % of plozasiran‑treated participants achieved triglycerides below 500 mg/dL, compared with approximately 50 % of placebo recipients, and over 50 % reached levels under 150 mg/dL.
A pooled analysis showed a 78 % relative reduction in acute pancreatitis events overall. Among patients with baseline triglycerides ≥ 500 mg/dL and a prior history of pancreatitis, the event rate fell by 91 % versus placebo.
Treatment‑emergent adverse events were reported in 73 % of both the active and placebo arms; serious adverse events occurred in 8.3 % of plozasiran patients versus 10 % of placebo patients. The most frequent adverse events in the plozasiran group were worsening glycaemic control (14.3 %) and diarrhea (5.6 %). Three deaths occurred among plozasiran‑treated patients—two cardiovascular deaths and one death from chronic myelomonocytic leukaemia—and were assessed as unrelated to the study drug.
Arrowhead intends to submit a supplemental New Drug Application to the U.S. Food and Drug Administration by the end of 2026, and will apply a Priority Review Voucher that the company purchased on 4 August 2026. Plozasiran is already approved as REDEMPLO for familial chylomicronemia syndrome in the United States, Canada, China, Australia, and the European Union.