Alnylam Pharmaceuticals Inc. (ALNY) announced on Monday that it will no longer pursue its supplemental new drug application (sNDA) for patisiran as a treatment for the cardiomyopathy of transthyretin-mediated (ATTR) amyloidosis. This decision comes after the company received a complete response letter from the U.S. Food and Drug Administration.
Patisiran is already approved for the treatment of the polyneuropathy of hereditary ATTR amyloidosis in adults. However, the FDA’s complete response letter means that the sNDA for patisiran cannot be approved at this time. It is important to note that this does not affect the drug’s approval for the other indication.
According to Alnylam Pharmaceuticals, the complete response letter stated that the clinical meaningfulness of patisiran’s treatment effects for the cardiomyopathy of ATTR amyloidosis has not been established. Therefore, the sNDA for patisiran could not be approved in its present form.
In light of this development, Alnylam Pharmaceuticals will shift its focus to the HELIOS-B Phase 3 study of vutrisiran. Vutrisiran is an investigational RNAi therapeutic that is administered subcutaneously once every three months. It is being developed as a treatment for the cardiomyopathy of ATTR amyloidosis. Additionally, Alnylam will also prioritize the development of ALN-TTRsc04, which is dosed annually.
ATTR amyloidosis is a severely underdiagnosed, rapidly progressive, debilitating, and fatal disease. It is caused by misfolded transthyretin (TTR) proteins, which accumulate as amyloid deposits in various parts of the body, including the nerves, heart, and gastrointestinal tract.
Alnylam Pharmaceuticals’ stock was halted premarket following this news.