Six of 10 members of the FDA Peripheral and Central Nervous System Drugs Advisory Committee decided there is not enough evidence to support approval of the drug from Amylyx Pharmaceuticals. The evidence from a single phase 2 trial is insufficient, the panel said.
The fate of the drug, known as AMX0035, and the panel’s vote, has been closely watched as new treatments for this devastating disease are greatly needed. Committee members said they were moved by passionate testimony from patients, caregivers, and others. But, they believe the evidence does not meet the required standard for FDA approval.
“We were asked to look for substantial evidence of persuasiveness and robustness, and I think this one trial doesn’t quite meet that bar and was problematic,” said Kenneth Fischbeck, MD, investigator with the National Institute of Neurological Disorders and Stroke. “It would be a disservice to patients and their families to move ahead and approve a treatment that is of uncertain benefit,” said Dr. Fischbeck.
The committee’s vote is not binding. While the FDA often follows its advisors’ decisions, the agency last year approved a controversial new drug for Alzheimer’s disease after a similar advisory committee voted against it.
Phase 3 study in the works
This new ALS drug was shown to slow the decline caused by ALS, sometimes known as Lou Gehrig’s disease, Jamie Timmons, MD, head of scientific communications at Amylyx Pharmaceuticals, said. The study found the drug slowed decline by 25%, compared with patients taking a placebo. That change is considered clinically meaningful.
This is the first time a treatment has shown a benefit on both function and survival in ALS, the two key measures in a relentlessly progressive, fatal disease, said Joshua Cohen, co-CEO and co-founder of Amylyx.
During the meeting, patients with ALS said they were willing to accept greater risk for the possibility of having even a little more time with their loved ones and argued that the drug contains two compounds that are already available. They pleaded for the FDA to exercise its regulatory flexibility in approving this experimental drug.
However, the FDA panel raised a number of issues with the trial. These concerns included the study’s small sample size and no survival benefit at 24 weeks.
Many panel members said they hope an ongoing phase III trial will be more definitive because it’s so much larger. The results of that trial are expected by early 2024.
A version of this article first appeared on WebMD.com.