FDA Approves Alnylam's Amvuttra for Rare Heart Disease ATTR-CM

Alnylam Pharmaceuticals has achieved a significant milestone with the approval of its drug Amvuttra (vutrisiran) by the Food and Drug Administration (FDA) for the treatment of transthyretin amyloid cardiomyopathy (ATTR-CM). This serious heart condition involves the buildup of misfolded transthyretin (TTR) proteins, leading to irreversible damage to the cardiovascular system. ATTR-CM, which affects approximately 150,000 individuals in the United States, can be life-threatening. A large number of patients remain undiagnosed or untreated, and even those receiving conventional therapies often continue to experience disease progression.

Amvuttra is an RNAi therapeutic specifically designed to address the cardiomyopathy associated with both wild-type and hereditary forms of TTR-mediated amyloidosis in adults. The treatment aims to lower cardiovascular mortality, decrease hospital admissions, and reduce urgent heart failure visits. The drug is administered quarterly via a subcutaneous injection and operates by rapidly reducing the levels of TTR in the body. Notably, Amvuttra is already approved in the United States for treating the polyneuropathy associated with hereditary TTR amyloidosis.

Yvonne Greenstreet, CEO of Alnylam Pharmaceuticals, emphasized the significance of this FDA approval, stating that Amvuttra offers a clinically unique treatment option that can lead to better outcomes for ATTR-CM patients. This includes reducing cardiovascular mortality and slowing disease progression, providing new hope for those battling this challenging condition.

The FDA's decision was supported by promising results from the phase 3 HELIOS-B trial. This study demonstrated that Amvuttra achieved statistical significance in comparison to placebo across all ten pre-specified primary and secondary endpoints. The trial enrolled a diverse group of patients reflective of the real-world population affected by this disease. In the general study population, which included patients receiving Amvuttra alone and those using it in combination with standard treatments, the drug reduced the risk of all-cause mortality (ACM) and recurrent cardiovascular events by 28% during the double-blind treatment phase, which lasted up to 36 months.

For patients receiving Amvuttra as a monotherapy, there was a 33% reduction in the risk of ACM and recurrent cardiovascular events during the double-blind period. Additionally, at 42 months, there was a 35% reduction in the risk of mortality, with mortality in the overall population decreasing by 36% at the same time point.

Dr. Ronald Witteles, a principal investigator in the HELIOS-B trial and affiliated with the Stanford University School of Medicine and Stanford Amyloid Center, expressed optimism about the clinical benefits demonstrated by Amvuttra. He highlighted the drug's ability to provide meaningful improvements in cardiovascular outcomes and measures of disease progression, underscoring the significance of these findings for patients grappling with this complex disease.

The approval of Amvuttra marks a pivotal development in the treatment landscape for ATTR-CM, offering a new therapeutic avenue for patients who have limited options. With this advancement, Alnylam Pharmaceuticals continues to make strides in addressing unmet medical needs in the field of amyloidosis, providing hope and improved quality of life for patients and their families.