Alnylam Pharmaceuticals has shared positive results from a late-stage study of its investigational RNAi therapeutic, vutrisiran, in transthyretin amyloidosis (ATTR) with cardiomyopathy.
The phase 3 HELIOS-B trial randomised 655 adults with the heart condition to receive vutrisiran or placebo subcutaneously once every three months for up to three years, after which all eligible patients were given the therapy in an open-label extension period.
Detailed results presented at this year’s European Society of Cardiology Congress showed that vutrisiran reduced the risk of all-cause mortality and recurrent cardiovascular events by 28% in the overall study population, which included patients receiving vutrisiran as a monotherapy and those using the therapy alongside standard treatments such as SGLT2 inhibitors and Pfizer’s Vyndaqel/Vyndamax (tafamidis).
In the monotherapy population, vutrisiran reduced the risk of all-cause mortality and recurrent cardiovascular events by 33% and the risk of mortality by 35% at month 42. Mortality in the overall population was reduced by 31% during the double-blind period and by 36% at month 42.
Vutrisiran was also associated with benefits across multiple clinical measures of disease progression, including the six-minute walk test, and subgroup analyses demonstrated consistent benefits across all key patient groups.
ATTR amyloidosis is an underdiagnosed and rapidly progressive disease caused by misfolded transthyretin (TTR) proteins, which accumulate as amyloid deposits in various parts of the body, including the heart and nerves. Patients may present with polyneuropathy, cardiomyopathy or both.
Alnylam’s vutrisiran is designed to works with your body’s natural system to rapidly knock down TTR and already holds approvals under the brand name Amvuttra to treat polyneuropathy caused by ATTR in adults.
The company’s chief medical officer, Pushkal Garg, said: “With this study, we have demonstrated that the rapid knockdown of toxic TTR seen with vutrisiran improves survival, and reduces cardiovascular hospitalisations and disease progression versus placebo, with benefits consistently observed across populations and regardless of background stabiliser use.
“While the results have not yet been reviewed by a regulatory authority, the data we have shared… suggests that vutrisiran has the potential to become a new standard of care treatment for ATTR with cardiomyopathy, a progressive and ultimately fatal disease with limited treatment options.”
Alnylam said it “remains on track” to proceed with global regulatory submissions for vutrisiran starting later this year.