Alnylam Pharmaceuticals Inc. scored FDA clearance for Amvuttra (vutrisiran), an RNAi therapeutic given via subcutaneous injection once every three months for the treatment of polyneuropathy in hereditary transthyretin-mediated (hATTR) amyloidosis in adults.

A rare, inherited, rapidly progressive and fatal disease with debilitating polyneuropathy traits, hATTR amyloidosis has few treatment options. Approval of Amvuttra was based on positive nine-month data from the Helios-A phase III study, where the drug significantly improved the signs and symptoms of polyneuropathy, with more than 50% of patients experiencing stoppage or reversal of their disease manifestations.

Helios-A turned up statistically significant improvements as measured by the modified Neuropathy Impairment Score, quality of life, gait speed, nutritional status and overall disability relative to external placebo data from the Apollo phase III trial with Alnylam’s Onpattro (patisiran), approved in August 2018 for the same indication pursued with Amvuttra. Alnylam expects to launch Amvuttra in early July, and the average annual list price for Amvuttra, before gross to net sales deductions, will be $463,500 per patient per year, consistent with Onpattro’s cost, the company said.

Next up: data with Onpattro in Apollo-B with Onpattro in ATTR cardiomyopathy, due around the middle of this year and widely anticipated. The phase III experiment – randomized, double-blinded, and placebo-controlled at multiple centers – includes 360 adults with ATTR amyloidosis (hereditary or wildtype). Patients were randomized 1-to-1 to get 0.3 mg/kg of Onpattro or placebo intravenously every three weeks over a 12-month treatment period. Apollo-B consists of a 12-month, double-blind, placebo-controlled period and a 36-month open-label extension period (during which all patients get Onpattro). The primary outcome measure is change from baseline in the six-minute walk test at 12 months. Begun in mid-2019, the trial finished in May 2021.

Alnylam CEO Yvonne Greenstreet said June 9 during a health care conference sponsored by Jefferies that the company has “a number of secondary endpoints, not including outcome measures” in Apollo-B, and officials at the firm are “excited about turning the card on the study,” because of their confidence in the way it was designed and executed.”

Shares of Cambridge, Mass.-based Alnylam (NASDAQ:ALNY) were trading at $136.08, up $8.38.