Alnylam Announces Receipt of Complete Response Letter from U.S. FDA for Supplemental New Drug Application for Patisiran for the Treatment of the Cardiomyopathy of ATTR Amyloidosis

– FDA Cites Insufficient Evidence of Clinical Meaningfulness –
– No Clinical Safety, Study Conduct, Drug Quality or Manufacturing Issues Identified –
– CRL Does Not Pertain to, nor Impact Commercial Availability of, ONPATTRO® (patisiran) for Existing Indication for the Treatment of the Polyneuropathy of Hereditary ATTR Amyloidosis in Adults –
– Alnylam to Host Investor Conference Call Today, Monday, October 9, 2023 at 8:30 a.m. ET –

CAMBRIDGE, Mass.–(BUSINESS WIRE)– Alnylam Pharmaceuticals, Inc. (Nasdaq: ALNY), the leading RNAi therapeutics company, today announced that the U.S. Food and Drug Administration (FDA) has issued a Complete Response Letter (CRL) in response to the Company’s supplemental New Drug Application (sNDA) for patisiran for the treatment of the cardiomyopathy of transthyretin-mediated (ATTR) amyloidosis.

Patisiran is the established name for ONPATTRO®, which is approved by the FDA for the treatment of the polyneuropathy of hereditary ATTR amyloidosis in adults. The CRL does not pertain to, nor does it impact commercial availability of, ONPATTRO for this existing indication.

The CRL indicated that the clinical meaningfulness of patisiran’s treatment effects for the cardiomyopathy of ATTR amyloidosis had not been established, and therefore, the sNDA for patisiran could not be approved in its present form. The CRL did not identify any issues with respect to clinical safety, study conduct, drug quality or manufacturing.

As a result of the CRL, the Company will no longer pursue an expanded indication for patisiran in the U.S. The Company remains dedicated to the ATTR amyloidosis community and will continue to focus on the HELIOS-B Phase 3 study of vutrisiran, an investigational RNAi therapeutic subcutaneously administered once every three months in development for the treatment of the cardiomyopathy of ATTR amyloidosis, and ALN-TTRsc04, which utilizes the Company’s IKARIA technology, with the potential for greater than 90% TTR knockdown with once annual dosing.