Their company financed the bulk of the study, but the A.L.S. Association, a patient advocacy group, contributed $2.2 million, using money raised through the 2014 Ice Bucket Challenge. Amylyx agreed to use sales of the drug to repay 150 percent of the association’s grant to fund more research.
Two-thirds of 137 participants in the Phase 2 trial received AMX0035, a bitter-tasting powder mixed with water to be drunk or ingested through a feeding tube twice daily. The rest received a placebo.
The primary goal was to slow decline on a 48-point A.L.S. scale rating 12 physical abilities, including walking, speaking, swallowing, dressing, handwriting and breathing. Over 24 weeks, patients receiving a placebo declined 2.32 points more than those taking AMX0035, translating to a 25 percent slower decline for patients receiving the treatment.
The open-label extension study involved 90 of those patients, including 34 from the placebo group, who began taking AMX0035 about seven months after those who had received it from the beginning. Those who received the treatment the longest had a median of 4.8 months more time before being hospitalized, being put on a ventilator or dying, Amylyx reported.
“This is the first time that we have seen a benefit in both function and survival in an A.L.S. clinical trial,” said Dr. Sabrina Paganoni, the principal investigator of the clinical trial and a neuromuscular medicine specialist at Massachusetts General Hospital’s Healey Center for A.L.S.
“If access is delayed, the patients in my clinic today may never receive the time and function that they could have had,” she added.
F.D.A. reviewers, however, identified many issues with the research.
Dr. Emily Freilich, a leader of the F.D.A. team, said Wednesday that the Phase 2 trial results suggesting that AMX0035 slowed functional decline were “not highly persuasive” and that the trial’s secondary measures — including muscle strength, respiratory ability and whether patients were hospitalized — were “not generally supportive” of benefit.