A novel investigational therapy currently being tested in clinical trials may become a treatment option for patients with hereditary transthyretin amyloidosis (hATTR), according to a news release from Alnylam Pharmaceuticals, Inc.

This phase 3 trial evaluated the efficacy and safety of patisiran, which is designed to treat hATTR patients with cardiomyopathy. This experimental treatment successfully improved the participants’ 6-minute walk test measurements from baseline to after 12 months of treatment, compared to those of the placebo group.

“We are thrilled that APOLLO-B successfully met all its major objectives, which we believe for the first time validates the hypothesis that TTR silencing by an [RNA interference (RNAi)] therapeutic can be an effective approach for treating the cardiomyopathy of ATTR amyloidosis,” Pushkal Garg, MD, chief medical officer of Alnylam, explained.

Moreover, the Kansas City Cardiomyopathy Questionnaire (KCCQ) exhibited a higher score increase among the participants treated with patisiran vs those treated with placebo. In addition, all-cause mortality and cardiovascular event frequency showcased positive results, although these were not statistically significant.

Read more about experimental therapies for hATTR

The randomized, double-blind, multicenter research included 360 patients from 21 different countries who were previously diagnosed with either hereditary or wild-type ATTR and were at least 18 years of age. The participants who received patisiran were administered 0.3 mg/kg via intravenous infusion every 3 weeks for 12 months.

Adverse events occurred in 91.2% of the patients in the patisiran group, which was similar to the rate of 94.4% in the placebo group. Serious adverse events occurred in 33.7% and 35.4% of participants in the patisiran and placebo groups, respectively. Most of the reactions in patients receiving patisiran were related to the intravenous administration, followed by arthralgia and muscle spasms.

“We look forward to sharing full results at an upcoming conference in September, and based on these positive results, we plan to submit a supplemental [New Drug Application] for patisiran with the US Food and Drug Administration in late 2022,” Dr. Garg said.


Alnylam reports positive topline results from APOLLO-B phase 3 study of patisiran in patients with ATTR amyloidosis with cardiomyopathy. News release. Alnylam Pharmaceuticals, Inc; August 3, 2022.