FDA Approves Arrowhead’s Redemplo for FCS

Rare Daily Staff

The U.S. Food and Drug Administration approved Arrowhead Pharmaceuticals’ Redemplo as an adjunct to diet for reducing triglycerides in adults with the rare genetic disorder familial chylomicronemia syndrome.

Familial chylomicronemia syndrome (FCS), is a disorder characterized by extremely high triglyceride levels—often greater than 880 mg/dL. These dangerously elevated levels can trigger a range of serious and sometimes life-threatening complications, including acute pancreatitis, chronic abdominal pain, diabetes, hepatic steatosis, and cognitive impairment. Despite the severity of the condition, treatment options for FCS have remained limited.

Redemplo is an siRNA therapeutic that works by suppressing production of apoC-III, a liver-produced protein that raises triglyceride levels by hindering their breakdown and clearance. Through sustained silencing of apoC-III, Redemplo achieves significant reductions in triglyceride levels. It is the first and only FDA-approved siRNA treatment evaluated in both genetically and clinically diagnosed patients living with FCS.

Redemplo received Breakthrough Therapy, Fast Track, and Orphan Drug designations from the FDA for FCS, as well as Orphan Medicinal Product designation from the European Medicines Agency for the same indication.

Approval was backed by data from the Phase 3 PALISADE study, a randomized, double-blind, placebo-controlled trial enrolling adults with either clinically diagnosed or genetically confirmed FCS. The trial met its primary endpoint and all key secondary endpoints, showing robust reductions in both triglyceride and apoC-III levels. Patients who received 25 milligrams of Redemplo achieved deep and durable triglyceride reductions—a median change from baseline of minus 80 percent, compared with minus 17 percent for pooled placebo—and experienced fewer episodes of acute pancreatitis than those in the placebo group.

The most common side effects reported among Redemplo-treated patients (occurring in at least 10 percent of those taking the drug, and at least 5 percent more frequently than with placebo) included hyperglycemia, headache, nausea, and injection site reactions. The FDA-approved package insert lists no contraindications, warnings, or precautions for Redemplo.

“Because FCS symptoms are mostly invisible, this community historically has often been overlooked and misunderstood, making their journey to effective treatment especially difficult,” said Lindsey Sutton Bryan, co-founder and co-president of the FCS Foundation. “Plozasiran offers real hope for a better future and shows what’s possible when innovation is driven by empathy and collaboration in addressing patients in need.”