ALNY Alnylam Pharmaceuticals Inc

By Colin Kellaher

The U.S. Food and Drug Administration has rejected Alnylam Pharmaceuticals' request for expanded approval of Onpattro for transthyretin-mediated amyloidosis with cardiomyopathy, or ATTR-CM, citing insufficient evidence of clinical meaningfulness.

Alnylam on Monday said it no longer plans to pursue the expanded indication after the FDA issued a so-called complete response letter, indicating the agency won't approve the application in its current form.

Alnylam said the FDA found that the Cambridge, Mass., company hadn't established the clinical meaningfulness of Onpattro's treatment effects for the cardiomyopathy of ATTR amyloidosis.

An FDA advisory committee last month had voted that the benefits of Onpattro outweigh its risks for the treatment of the cardiomyopathy of ATTR amyloidosis, but panel members also suggested that the drug would only be useful for patients who worsen while receiving Pfizer's tafamidis franchise of Vyndaqel and Vyndamax, and some Wall Street analysts had cautioned that the FDA's ultimate decision would be a tossup.

Alnylam said the FDA didn't identify any issues with clinical safety, drug quality or manufacturing, adding that the decision doesn't affect Onpattro for its approved indication in the polyneuropathy of hereditary ATTR amyloidosis in adults.

Trading in shares of Alnylam, which closed Friday at $176.92, was halted premarket on Monday.

Write to Colin Kellaher at colin.kellaher@wsj.com

(END) Dow Jones Newswires

October 09, 2023 08:08 ET (12:08 GMT)

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