Arrowhead Pharmaceuticals Inc. (NASDAQ: ARWR) presented two-year efficacy and safety data for plozasiran in treating hypertriglyceridemia at the American College of Cardiology's 75th Annual Scientific Session in New Orleans.

The open-label extension study showed patients with severe hypertriglyceridemia achieved an 83% median reduction in triglycerides, with 96% of patients reaching triglyceride levels below 500 mg/dL. No acute pancreatitis events occurred during the two-year study period.

Patients with hypertriglyceridemia experienced a 67% median reduction in triglycerides, with 93% achieving levels below 150 mg/dL. The study also showed improvements in atherogenic lipoproteins, including remnant cholesterol, non-HDL cholesterol, and ApoB.

Dr. Christie M. Ballantyne from Baylor College of Medicine, the study's principal investigator, presented the findings. "In a long-term open-label extension study, plozasiran treatment was associated with dramatic and meaningful reductions in TGs," Ballantyne said.

The safety profile remained consistent with earlier trials, with common adverse events including diabetes, COVID-19, upper respiratory tract infection, and back pain. HbA1c levels remained stable throughout the study.

Plozasiran works by reducing hepatic production of apolipoprotein C-III through RNA interference, which regulates triglyceride metabolism. The company received FDA approval for plozasiran under the brand name REDEMPLO for treating familial chylomicronemia syndrome in 2024.

Arrowhead plans to complete Phase 3 studies SHASTA-3, SHASTA-4, and MUIR-3 by mid-2026 and intends to submit a supplemental New Drug Application to the FDA by year-end 2026 for severe hypertriglyceridemia treatment.

The data were published in the American Journal of Preventive Cardiology alongside the conference presentation.