Arrowhead Pharmaceuticals Wins EU Approval for REDEMPLO® to Lower Triglycerides in Adults with Familial Chylomicronemia Syndrome
Arrowhead Pharmaceuticals has secured an important regulatory milestone in Europe with the European Commission’s marketing authorization of REDEMPLO® (plozasiran) for adults living with familial chylomicronemia syndrome (FCS). The approval authorizes the small interfering RNA (siRNA) medicine as an adjunct to diet to reduce triglyceride levels in adult patients with FCS, a rare and serious genetic lipid disorder associated with extremely high triglycerides and a substantial risk of recurrent acute pancreatitis.
The decision gives Arrowhead a new foothold in the European rare disease market and further expands the global commercial reach of REDEMPLO, which has already gained approvals in other major territories. In the European Union, REDEMPLO becomes the first and only siRNA medicine authorized for adults with FCS, including patients diagnosed either through clinical criteria or by genetic testing.
That breadth of eligibility is a notable aspect of the label because it may allow treatment to begin in patients whose disease is clinically apparent even if confirmatory genetic testing is not immediately available. The European Medicines Agency previously highlighted this as a meaningful advantage, noting that REDEMPLO offers an option for adults with FCS without requiring genetic confirmation of the condition, thereby helping address an important unmet need in this patient population. (European Medicines Agency (EMA))
A Rare Lipid Disorder With Serious Consequences
Familial chylomicronemia syndrome is one of the most severe forms of hypertriglyceridemia. People living with the disease can experience triglyceride levels that are dramatically higher than normal, often reaching concentrations associated with a high risk of acute, recurrent, and potentially fatal pancreatitis. In addition to pancreatitis, patients may face chronic abdominal pain, severe dietary restrictions, fatigue, anxiety around food intake, and long diagnostic delays before the disease is recognized.
Because FCS is rare and frequently underdiagnosed, treatment options have historically been limited, and patients often rely on extremely restrictive low-fat diets alongside supportive management strategies. For many individuals, those interventions alone are not enough to adequately control triglycerides or reduce the threat of pancreatitis. That has made the search for targeted therapies a priority in rare lipid disorders and created a significant unmet need for medicines that can directly address the biological drivers of triglyceride accumulation.
Arrowhead’s approval in Europe is therefore more than a conventional market expansion. It adds another therapeutic option for a patient group that has long had very few effective treatments and may also improve access for individuals whose diagnosis is based on clinical presentation rather than solely on genetic testing.
Why the European Approval Matters
The European Commission’s decision is significant for several reasons. First, it formally validates REDEMPLO’s clinical package in one of the world’s most important pharmaceutical markets, opening the door to commercialization across European Union member states. Second, it reinforces the growing momentum behind Arrowhead’s RNA interference platform, which has now translated into a marketed product across multiple geographies. Third, it broadens the reach of a therapy that addresses a disease with high medical need but limited treatment alternatives.
The approval follows a positive opinion from the Committee for Medicinal Products for Human Use (CHMP), which in April 2026 recommended the drug for authorization in the European Union. EMA materials describe REDEMPLO as a 25 mg pre-filled syringe formulation of plozasiran, an siRNA conjugated with N-acetylgalactosamine designed to selectively silence the messenger RNA for apolipoprotein C-III (APOC3) in hepatocytes. By lowering APOC3, the therapy is intended to improve the breakdown and clearance of triglyceride-rich lipoproteins, ultimately reducing circulating triglyceride levels. (European Medicines Agency (EMA))
For clinicians and patients, one of the most practical implications of the EU label is the ability to treat both genetically confirmed and clinically diagnosed FCS. In rare diseases, delays in diagnosis can be common, and access to genetic testing may vary by geography, healthcare system, or clinical setting. A therapy that can be prescribed on the basis of recognized clinical criteria may therefore help shorten the time between disease recognition and treatment initiation.
Professor Børge Nordestgaard of the University of Copenhagen and President of the European Atherosclerosis Society emphasized the importance of that flexibility, noting that FCS places patients at elevated risk of recurrent and potentially fatal episodes of acute pancreatitis. He pointed to data from the PALISADE study showing that plozasiran can drive significant and sustained reductions in triglycerides, while also underscoring that treatment without a mandatory genetic test could enable earlier intervention in a rare disease where timing can matter greatly.
How REDEMPLO Works
REDEMPLO is built on Arrowhead’s proprietary Targeted RNAi Molecule (TRiM™) platform, which uses RNA interference to selectively reduce the production of disease-driving proteins. In the case of plozasiran, the target is apolipoprotein C-III (apoC-III), a liver-produced protein that plays an important role in triglyceride metabolism.
APOC3 raises triglyceride levels by interfering with their breakdown and clearance. It inhibits lipoprotein lipase activity and slows the removal of triglyceride-rich lipoprotein remnants from circulation. In FCS, where triglyceride metabolism is already profoundly disrupted, suppressing APOC3 offers a mechanistically direct way to lower triglycerides and potentially reduce the downstream risk of pancreatitis.
By silencing the APOC3 pathway, REDEMPLO is intended to provide a durable reduction in triglyceride burden rather than simply treating symptoms or relying exclusively on diet. That mechanism has helped position plozasiran as a first-in-class RNAi-based therapy in the FCS space and a showcase product for Arrowhead’s broader siRNA pipeline.
PALISADE Data Underpinned the Approval
The European Commission’s authorization was supported by results from the Phase 3 PALISADE trial, a randomized, double-blind, placebo-controlled study conducted in 75 adults with clinically diagnosed or genetically confirmed FCS. The trial met its primary endpoint as well as all multiplicity-controlled key secondary endpoints, providing the core evidence base for global regulatory submissions. (European Medicines Agency (EMA))
In PALISADE, patients receiving 25 mg REDEMPLO achieved a median 80% reduction in triglycerides from baseline, compared with a 17% reduction in the placebo arm. That degree of triglyceride lowering is especially meaningful in a disease where triglyceride levels can be extraordinarily high and where sustained control is central to reducing pancreatitis risk. The study also showed that pooled plozasiran doses of 25 mg and 50 mg significantly reduced the incidence of acute pancreatitis, with an odds ratio of 0.169 and a p-value of 0.0292. According to Arrowhead, the odds of acute pancreatitis were 83% lower in the pooled plozasiran groups compared with placebo. (Arrowhead Pharmaceuticals, Inc.)
Those pancreatitis findings are particularly important because triglyceride reduction alone, while clinically meaningful, is only part of the story in FCS. What patients and physicians ultimately care about most is whether treatment lowers the risk of painful, dangerous, and potentially life-threatening pancreatitis episodes. PALISADE suggests that plozasiran may do both: dramatically reduce triglycerides and lower the incidence of acute pancreatitis.
In terms of safety, the most commonly reported adverse reactions included hyperglycaemia, headache, nausea, and injection-site reactions. EMA’s summary of the product similarly lists hyperglycaemia, headache, nausea, and injection site reactions among the most common side effects observed in clinical testing. (European Medicines Agency (EMA))
Arrowhead Expands a Growing Global Footprint
For Arrowhead, the EU approval is part of a broader sequence of regulatory progress for REDEMPLO. The therapy has already been cleared in the United States, Canada, China, and Australia, and the company has been steadily building a global commercialization strategy around the product. In China, REDEMPLO is being launched through Sanofi under a regional agreement, while in other territories Arrowhead has continued to advance access through direct regulatory filings and local engagement. (Arrowhead Pharmaceuticals Inc.)
Christopher Anzalone, Ph.D., Arrowhead’s president and chief executive officer, said the company is pleased to have secured EC approval for REDEMPLO as a new treatment option for people living with genetically or clinically confirmed FCS. He noted that Arrowhead is now engaging with national authorities and healthcare communities across the European Union to bring the medicine to patients as quickly and efficiently as possible. He also framed the approval as part of a broader cadence of regulatory progress that reflects both the strength of the plozasiran clinical data and the wider promise of Arrowhead’s TRiM platform across a diverse siRNA pipeline.
That broader pipeline context matters. Arrowhead has spent years positioning itself as a leader in RNA interference therapeutics, and REDEMPLO represents one of the clearest commercial validations of that strategy to date. Each new regulatory approval not only expands the market opportunity for plozasiran, but also strengthens the company’s credibility as a commercial-stage RNAi developer capable of bringing complex therapies from platform science through late-stage development and into global markets.
A Potential Shift in the FCS Treatment Landscape
The approval also has symbolic importance for the FCS community. Rosa Pérez Jiménez, president of Spain’s Familial Chylomicronemia Association, described the decision as a pivotal moment for people living with the disease. Speaking both as a patient and as an advocate, she highlighted the daily burden of FCS, including the fear of acute pancreatitis, chronic pain, fatigue, and the long, often frustrating path to diagnosis. In that context, the arrival of a new treatment option represents not only medical progress but also validation for a patient community that has often felt overlooked.
That sentiment captures why REDEMPLO’s European authorization could have an impact beyond its immediate clinical profile. FCS is a rare disease, but for affected patients it is life-defining. A therapy that can be used in both clinically diagnosed and genetically confirmed adults, and that has demonstrated substantial triglyceride reductions alongside lower pancreatitis incidence, may help shift the standard of care in a way that is meaningful for patients, physicians, and healthcare systems alike.
The next phase for Arrowhead will center on execution. European Commission approval grants access to the EU market, but commercial success will depend on reimbursement negotiations, country-by-country launch planning, physician education, and patient identification in a disease that remains underrecognized. Rare disease launches often hinge not just on regulatory clearance but on how effectively a company can build awareness, support diagnosis, and navigate national access pathways.
Still, the approval of REDEMPLO in Europe marks a clear advance for both Arrowhead and the FCS field. For Arrowhead, it adds another major market to the company’s first commercial RNAi franchise and reinforces the value of its TRiM platform. For patients with familial chylomicronemia syndrome, it offers a new therapeutic option backed by Phase 3 data showing robust triglyceride lowering and a meaningful reduction in acute pancreatitis risk.
At a broader level, the decision is another sign that RNA interference medicines are continuing to move beyond niche scientific promise into practical, global therapeutic use. With REDEMPLO now authorized in Europe, Arrowhead has strengthened its position in rare metabolic disease and taken another step toward establishing siRNA therapeutics as a durable commercial class in serious and underserved conditions.
About Familial Chylomicronemia Syndrome (FCS)
Familial chylomicronemia syndrome is a severe and rare disease leading to extremely high triglyceride (TG) levels, typically over 10 mmol/L (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.
About REDEMPLO® (plozasiran)
REDEMPLO (plozasiran) is currently approved by the U.S. Food and Drug Administration, Health Canada, China’s National Medical Products Administration, the Australian Therapeutic Goods Administration, and by the European Commission as an adjunct to diet to reduce triglycerides for adults with FCS. REDEMPLO is the first and only siRNA treatment approved in these countries to be studied in both clinically diagnosed and genetically confirmed patients living with FCS.
REDEMPLO is designed to suppress the production of apolipoprotein C-III (APOC3), a protein produced in the liver that raises triglyceride levels by slowing their breakdown and clearance. By targeting APOC3 with sustained silencing, REDEMPLO delivers significant reductions in triglyceride levels. REDEMPLO is self-administered via subcutaneous injection once every three months.
REDEMPLO has been granted Orphan Medicinal Product Designation by the EMA for the treatment of patients with FCS, and Breakthrough Therapy Designation, Fast Track Designation, and Orphan Drug Designation by the U.S. FDA for the treatment of patients with FCS. In December 2025, plozasiran was also granted Breakthrough Therapy designation by the U.S. FDA in severe hypertriglyceridemia.
Plozasiran is also being investigated in the SHASTA-3 (NCT06347003), SHASTA-4 (NCT06347016), and SHASTA-5 (NCT06880770) Phase 3 studies in adults with severe hypertriglyceridemia and the MUIR-3 (NCT06347133) Phase 3 study in adults with hypertriglyceridemia.
About Arrowhead Pharmaceuticals
Arrowhead Pharmaceuticals (NASDAQ: ARWR) is a commercial-stage pharmaceutical company developing medicines that treat intractable diseases by silencing the genes that cause them, harnessing the natural RNA interference (RNAi) mechanism. The company has built a broad portfolio of clinical and commercial RNAi therapeutics through its industry-leading targeted RNAi molecule (TRiM™) platform, which can precisely silence genes in a wide range of cell types, including liver, lung, muscle, adipose, and central nervous system tissue. At Arrowhead, we rapidly advance potential best- and first-in-class RNAi treatments for diseases with significant unmet medical need, because every day matters to the patients we serve.
