A top-line win for Pfizer Inc.'s tafamidis, a small-molecule drug in phase III testing to treat a rare and fatal condition associated with progressive heart failure, has shaken up competitive outlooks for Alnylam Pharmaceuticals Inc. and Ionis Pharmaceuticals Inc., both of which are developing alternate therapies in the space. The ATTR-ACT trial, in transthyretin cardiomyopathy, found tafamidis provided a statistically significant reduction in the combination of all-cause mortality and frequency of cardiovascular-related hospitalizations vs. placebo at 30 months. It was the first pivotal trial to test a pharmacological treatment for the condition.