Alnylam Pharma Down 11% In Pre-market Despite Positive Data From HELIOS-B Phase 3 Study

(RTTNews) - Alnylam Pharmaceuticals, Inc. (ALNY) Friday announced detailed results from the HELIOS-B Phase 3 study of vutrisiran for the treatment of ATTR amyloidosis with cardiomyopathy (ATTR-CM). Despite positive data, the stock was down more than 11 percent in pre-market to $254.25.

HELIOS-B Phase 3 study was designed to evaluate the efficacy and safety of vutrisiran on the reduction of all-cause mortality and recurrent cardiovascular events in patients with ATTR amyloidosis with cardiomyopathy.

In the study, 655 adult patients with ATTR amyloidosis, hereditary or wild-type, with cardiomyopathy were randomized to receive vutrisiran or placebo during a period of up to 36 months. After this period, all eligible patients were received vutrisiran in an open-label extension period of HELIOS-B.

Results from the study showed that treatment with vutrisiran substantially reduced the risk of death and cardiovascular events compared to placebo. In the overall population, vutrisiran reduced the risk of all-cause mortality and recurrent cardiovascular events by 28 percent. In the monotherapy population, vutrisiran significantly reduced the risk of all-cause mortality and recurrent cardiovascular events by 33 percent.

Earlier, HELIOS-B study had met all 10 of its primary and secondary endpoints, across both the overall and monotherapy populations.

Vutrisiran is already approved in the U.S. for the treatment of the polyneuropathy of hereditary transthyretin mediated amyloidosis (hATTR amyloidosis) in adults. In Europe and the UK, vutrisiran is approved for the treatment of hATTR amyloidosis in adult patients with stage 1 or stage 2 polyneuropathy.

The company said it remains on track to proceed with global regulatory submissions for vutrisiran starting later this year, including filing a supplemental New Drug Application with the U.S. Food and Drug Administration using a Priority Review Voucher.

Alnylam stock had closed at $287.01, up 2.25 percent on Thursday. The stock has traded in the range of $141.98 - $287.55 in the last 1 year.