Alnylam Presents 18-Month Results from the APOLLO-B Phase 3 Study of Patisiran in Patients with ATTR Amyloidosis with Cardiomyopathy

Alnylam Pharmaceuticals, Inc. (Nasdaq: ALNY), the leading RNAi therapeutics company, today announced new results from an interim analysis of exploratory data from the open-label extension (OLE) period of the APOLLO-B Phase 3 study of patisiran, an investigational RNAi therapeutic in development for the treatment of transthyretin-mediated (ATTR) amyloidosis with cardiomyopathy. The results were presented at the Annual Congress of the Heart Failure Association of the European Society of Cardiology (Heart Failure 2023; May 20-23, 2023). The Company previously announced that APOLLO-B achieved its primary endpoint and met its first secondary endpoint during the 12-month double-blind (DB) period and that it has submitted the 18-month data to the U.S. Food and Drug Administration (FDA) as an amendment to the supplemental New Drug Application (sNDA) for patisiran for the treatment of the cardiomyopathy of ATTR amyloidosis.

The 18-month findings indicate that the favorable effects on functional capacity and health status and quality of life, as measured by the 6-Minute Walk Test (6-MWT) and the Kansas City Cardiomyopathy Questionnaire Overall Summary (KCCQ-OS), respectively, observed during the DB period were sustained with continued patisiran treatment during the OLE period. Patients treated with patisiran through 18 months also appear to have maintained relative stability of NT-proBNP and Troponin I levels, measures of cardiac stress and injury, respectively. Patients who crossed over from placebo in the DB period to patisiran during the OLE period appear to show slowing of disease progression or relative stabilization across these same endpoints at Month 18. While the APOLLO-B study was not designed to show benefits in cardiac outcomes between patisiran and placebo, evidence of favorable, but non-statistically significant, trends were observed for composite all-cause death and hospitalization, and mortality analyses across the DB and OLE periods.

“We are pleased to share encouraging new data from our APOLLO-B OLE study, which we believe continue to support the potential for patisiran to be an important therapeutic option for patients with ATTR amyloidosis with cardiomyopathy,” said Rena N. Denoncourt, Vice President, TTR Franchise Lead. “The results demonstrate that serum TTR reduction with an RNAi therapeutic has the potential to provide sustained clinical benefit through 18 months of treatment. These data, in conjunction with the observed decline in placebo-treated patients during the DB period, reinforce the importance of early treatment initiation in ATTR amyloidosis. We remain steadfast in our commitment to bring patisiran to patients with ATTR amyloidosis with cardiomyopathy who currently have limited treatment options.”