PASADENA, Calif. — October 7, 2026
Arrowhead Pharmaceuticals, Inc. announced that the U.S. Food and Drug Administration (FDA) has granted plozasiran entry into the Split Real Time Application Review (STAR) pilot program in connection with the company’s planned supplemental new drug application (sNDA) for severe hypertriglyceridemia (sHTG). The regulatory milestone could accelerate the review of plozasiran for sHTG, a condition characterized by severely elevated triglyceride levels and an increased risk of acute pancreatitis, which can result in recurrent hospitalizations and potentially fatal complications. Entry into the FDA STAR program is intended for certain supplemental indications where clinical evidence suggests the approved drug may provide substantial improvement on clinically relevant endpoints compared with available therapies. Arrowhead said the designation provides an important opportunity to accelerate potential patient access to plozasiran as the company prepares its supplemental application for submission by year-end 2026.
FDA STAR Program Enables Faster Supplemental Review
Under the FDA STAR pilot program, qualifying supplemental applications receive a six-month Priority Review, compared with the standard 10-month review period. FDA may also generally target an expedited review for efficacy supplements participating in STAR, potentially resulting in regulatory action at least one month before the Priority Review goal date. Arrowhead noted that a Priority Review Voucher (PRV) is not required for an application accepted into the STAR program. This allows the company to retain the PRV it purchased in August 2026, potentially providing an option to redeploy the voucher for a future regulatory application or monetize it. The FDA’s acceptance of plozasiran into STAR reflects the agency’s determination that clinical evidence supporting the supplemental indication may demonstrate substantial improvement on clinically relevant endpoints. Arrowhead said the accelerated review pathway could help shorten the time between submission of a complete sNDA and a potential regulatory decision for the sHTG indication.
Plozasiran Targets APOC3 to Reduce Triglycerides
Plozasiran, marketed as REDEMPLO®, is an investigational expansion of an already approved siRNA therapy designed to reduce triglyceride levels by suppressing production of apolipoprotein C-III (APOC3) in the liver. APOC3 contributes to elevated triglyceride levels by slowing the breakdown and clearance of triglyceride-rich lipoproteins. By using sustained RNA interference to silence APOC3, plozasiran is designed to promote triglyceride reduction through improved clearance of these particles. REDEMPLO is currently approved in the United States, European Union, China, Australia and Canada as an adjunct to diet for adults with familial chylomicronemia syndrome (FCS), the most severe form of sHTG. The treatment is administered by subcutaneous injection once every three months. Arrowhead is now seeking to expand the potential use of plozasiran into the broader severe hypertriglyceridemia population, where treatment options capable of sustainably lowering triglycerides remain limited.
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Arrowhead Prepares sNDA Submission by Year-End
Arrowhead plans to submit the sNDA for plozasiran in severe hypertriglyceridemia to the FDA by the end of 2026, followed by regulatory submissions to additional global authorities. Severe hypertriglyceridemia is generally defined by triglyceride levels above 500 mg/dL, while the most severe cases such as FCS can involve levels exceeding 880 mg/dL. Rising triglyceride-rich lipoprotein concentrations can increase the risk of acute pancreatitis, while elevated triglycerides may also contribute to cardiovascular risk. With plozasiran already approved for FCS and now accepted into the FDA STAR pilot program for sHTG, Arrowhead is advancing the regulatory strategy for a broader patient population. The milestone strengthens the company’s effort to expand the reach of its RNA interference (RNAi)-based therapy and potentially provide an additional treatment option for patients with severe triglyceride disorders and significant unmet medical needs.
Source::Arrowhead Pharmaceuticals,, press release
