Alnylam Reports Positive Topline Results From 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 that the APOLLO-B Phase 3 study of patisiran, an investigational RNAi therapeutic in development for the treatment of transthyretin-mediated (ATTR) amyloidosis with cardiomyopathy, met the primary endpoint of change from baseline in the 6-Minute Walk Test (6-MWT) at 12 months compared to placebo (p-value 0.0162). The study also met the first secondary endpoint of change from baseline in quality of life compared to placebo, as measured by the Kansas City Cardiomyopathy Questionnaire (KCCQ) (p-value 0.0397).

The study also included additional secondary composite outcome endpoints to be tested in a hierarchical manner. A non-significant result (p-value 0.0574) was found on the secondary composite endpoint of all-cause mortality, frequency of cardiovascular events, and change from baseline in 6-MWT over 12 months compared to placebo. As a result, formal statistical testing was not performed on the final two composite endpoints, which were not powered for statistical significance given the short duration of the study — all-cause mortality and frequency of all-cause hospitalizations and urgent heart failure visits in patients not on tafamidis at baseline (nominal p-value 0.9888), and in the overall population (nominal p-value 0.5609). Patisiran also demonstrated an encouraging safety and tolerability profile, with deaths numerically favoring the patisiran arm.