Wednesday is going to be a very big day for folks with neurodegenerative disorders and a clinical-stage biopharmaceutical company called Amylyx Pharmaceuticals (AMLX -5.32%). On March 30, the FDA is meeting with independent neurologists to discuss the company's experimental treatment for amyotrophic lateral sclerosis (ALS).
Each year, around 6,000 American adults are diagnosed with ALS after complaining about muscle weakness. Nerve cells that carry signals from brains to muscles degrade at different rates for different ALS patients but most lose the use of their limbs and their ability to breathe independently three to five years after they begin noticing symptoms.
As is often the case with progressive neurodegenerative disorders, ALS treatment options are limited because we really aren't sure what causes the disease in the first place. Given the lack of disease-modifying ALS drugs out there, a positive result on Wednesday could send the stock soaring in anticipation of blockbuster sales.
FDA says the evidence isn't persuasive
Unfortunately, the speedy approval of AMX0035 before an ongoing phase 3 study reads out seems very unlikely. The agency finally told the public what it actually thinks about Amylyx's application package and it's not great.
Instead of secretly deciding the fate of high-profile drug candidates like AMX0035 in secret, the FDA holds public advisory committee meetings with panels of independent physicians to show the world that everybody's on the same page. At least this is the intention.
You may recall several members of the neurology committee resigned in protest last year after the agency ignored its negative recommendations and approved Aduhelm, a highly controversial treatment for Alzheimer's disease from Biogen. There probably won't be any resignations this year because the agency doesn't appear ready to accept the company's phase 2 data as sufficient evidence of efficacy and will most likely wait more than a year for phase 3 results.
Image source: Getty Images.
In its briefing document, the FDA reminded everyone that the agency is only willing to use phase 2 data to support an approval if said data is highly persuasive. The agency noted multiple problems with the design of Amylyx's phase 2 trial, including a measured benefit that just barely reached statistical significance.
The FDA reminded its advisory committee members that reliance on a single trial to establish effectiveness should be limited to situations in which the trial demonstrates a positive effect on mortality. The agency also said positive long-term survival results from an extension of the problematic phase 2 trial are also not persuasive evidence of efficacy because too many patients dropped out.
The good news
Given the FDA's stance, the odds of a speedy approval based on available data are close to zero right now. That isn't necessarily a reason to run from Amylyx stock though.
Side effects might not seem like a big deal when we're talking about diseases as lethal as ALS but they still matter to regulators. Luckily, the FDA noted that overall, treatment with AMX0035 didn't correlate with any serious safety risks.
The FDA didn't invite Amylyx to submit an early application just to slap it down in a public setting. The agency wanted to review all available data in an application setting upfront so it can approve AMX0035 as soon as possible once the company can produce successful phase 3 results.
The phase 3 Phoenix trial began last October and is expected to enroll up to 600 participants. Topline results are expected in November of 2023. The company just raised around $190 million in its initial public offering (IPO) this January so it shouldn't have too much trouble paying the bills until after Phoenix reads out. It might take longer than hoped, but we'll find out if AMX003 can become a blockbuster drug in a couple of years.
