お知らせ • Mar 28
Arrowhead Pharmaceuticals Presents New Long-Term Efficacy And Safety Data For Plozasiran Across A Spectrum Of Hypertriglyceridemia
Arrowhead Pharmaceuticals, Inc. announced long-term efficacy and safety data from a two-year long open-label extension (OLE) study of investigational plozasiran supporting its potential as therapeutic solution for a diverse spectrum of patients with hypertriglyceridemia (HTG). Patients with severe hypertriglyceridemia (sHTG) achieved an 83% median reduction in triglycerides (TG), with 96% of patients achieving TG levels below 500 mg/dL, a threshold associated with increased risk of acute pancreatitis. No adjudicated acute pancreatitis events occurred in any patient receiving plozasiran during the 2-year Phase 2b Open-Label Expansion (OLE) Study. Favorable and durable improvements in atherogenic lipoproteins, including remnant cholesterol, non-HDL cholesterol, and ApoB, were observed, with a safety profile consistent with earlier trials. Plozasiran is designed to reduce the hepatic production of apolipoprotein C-III (APOC3) through targeted RNA interference. APOC3 is a key regulator of triglyceride metabolism that inhibits both lipoprotein lipase (LPL)-dependent and LPL-independent pathways involved in triglyceride catabolism and clearance, leading to elevated triglyceride levels. Individuals with genetic loss-of-function variants in APOC3 typically have markedly lower triglyceride levels and a reduced risk of atherosclerotic cardiovascular disease. The ACC.26 presentation builds on positive findings from two Phase 2b double-blind, placebo-controlled studies of plozasiran: SHASTA-2, conducted in adults with severe hypertriglyceridemia (sHTG), and MUIR, which enrolled patients with hypertriglyceridemia, both of which demonstrated short-term efficacy and safety. With the same patient populations, the company initiated an extension phase in which both groups received plozasiran 25 mg quarterly via subcutaneous injections. During the two-year OLE, patients saw median reductions in their triglycerides by -83% in sHTG patients from SHASTA-2 and -67% in HTG patients from MUIR with favorable reductions in remnant cholesterol and non-HDL-cholesterol. In both studies, the majority of patients achieved TG levels below thresholds for acute pancreatitis (AP) risk or below normal thresholds. 96% of sHTG patients achieved TGs below 500 mg/dL and 63% achieved TGs below 150 mg/dL, a threshold associated with increased risk of ASCVD. 93% of HTG patients achieved TGs below 150 mg/dL. These findings support the potential of plozasiran as a promising approach for managing patients with moderate to severe HTG phenotypes who are at risk of AP and potentially other cardiometabolic comorbidities. Plozasiran demonstrated a consistent long-term safety and tolerability profile across both sHTG and HTG patient populations, with stable glycemic parameters, no clinically meaningful differences in routine clinical laboratory measurements, and no new safety signals. Common treatment-emergent adverse events included diabetes, COVID-19, upper respiratory tract infection, and back pain, consistent with prior studies; HbA1c levels remained stable. In SHASTA-2, mean placebo-adjusted liver fat content, as assessed by MRI-PDFF, did not change significantly over time with 25 mg plozasiran treatment. Arrowhead is on schedule to complete the SHASTA-3, SHASTA-4, and MUIR-3 Phase 3 clinical studies, the company’s global Phase 3 clinical studies designed to support regulatory submissions for marketing approval of plozasiran for the treatment of severe hypertriglyceridemia, in mid-2026 and intends to submit a supplemental New Drug Application (sNDA) to the U.S. FDA by year-end 2026. Arrowhead also plans to seek regulatory approval with additional global regulatory authorities thereafter. Severe hypertriglyceridemia (SHTG) is characterized by triglyceride (TG) levels greater than 500 mg/dL, with the most severe form being familial chylomicronemia syndrome (FCS) where TGs typically exceed 880 mg/dL. SHTG significantly increases the risk of acute pancreatitis (AP), which can often include recurrent attacks requiring repeat hospital admissions and worsening outcomes. AP risk is proportional to the number, characteristics, and concentration of triglyceride rich lipoproteins (TRLs), particularly chylomicrons, and increases as TGs rise. Elevated TGs can also increase the risk of atherosclerotic cardiovascular disease (ASCVD). Limited treatment options exist to sustainably reduce TGs below guideline directed risk thresholds. Familial chylomicronemia syndrome (FCS) is a severe and rare disease leading to extremely high triglyceride (TG) levels, typically over 880 mg/dL. Such severe elevations can lead to various serious signs and symptoms including acute and potentially fatal pancreatitis, chronic abdominal pain, diabetes, hepatic steatosis, and cognitive issues. Currently, there are limited therapeutic options to adequately treat FCS. Plozasiran is a first-in-class investigational RNA interference (RNAi) therapeutic designed to reduce production of apolipoprotein C-III (apoC-III) which is a component of triglyceride rich lipoproteins (TRLs) and a key regulator of triglyceride metabolism. ApoC-III increases triglyceride levels in the blood by inhibiting breakdown of TRLs by lipoprotein lipase and uptake of TRL remnants by hepatic receptors in the liver. The goal of treatment with plozasiran is to reduce the level of apoC-III, thereby reducing triglycerides and restoring lipids to more normal levels. Plozasiran is being investigated in the SHASTA-3, SHASTA-4, and SHASTA-5 Phase 3 studies in patients with severe hypertriglyceridemia and the MUIR Phase 3 study in patients with mixed hyperlipidemia. REDEMPLO (plozasiran) is approved by the U.S. Food and Drug Administration, Health Canada, and the Chinese National Medical Products Administration as an adjunct to diet to reduce triglycerides for adults with Familial Chylomicronemia Syndrome (FCS). REDEMPLO is an siRNA therapeutic designed to suppress the production of apoC-III, a protein produced in the liver that raises triglyceride levels by slowing their breakdown and clearance. By targeting apoC-III with sustained silencing, REDEMPLO delivers significant reductions in triglyceride levels. REDEMPLO is the first and only siRNA FDA-approved treatment studied in both genetically confirmed and clinically diagnosed patients living with FCS.
