Pomerantz Prevails Against Amylyx Pharmaceuticals
On September 30, 2025, Pomerantz secured a victory on behalf of a proposed class of investors in Amylyx Pharmaceuticals, Inc. (“Amylyx”), defeating the defendants’ motion to dismiss securities fraud claims related to Amylyx’s commercial launch of its drug, Relyvrio, a purported answer to the unmet need to address amyotrophic lateral sclerosis (“ALS”).
Judge Gordon (D. Mass.) denied the defendants’ motion to dismiss on the papers, without a hearing.
The Unmet Need for an ALS Cure
What began in 2014 as a simple call for participants to pour ice water over themselves soon became one of the most viral global social media challenges of the decade. The “ALS Ice Bucket Challenge” spread rapidly across social media, combining humor with advocacy and yielding a remarkable increase in public awareness to find a cure for ALS.
Fast forward to 2025, and there is still no cure for ALS—or even a drug that can mitigate the severe and life-threatening symptoms of this rare disease. The initial manifestations range from muscle weakness of the limbs to difficulty with speech and swallowing. Over time, patients develop muscle paralysis, inability to speak or swallow, and respiratory failure leading to certain death in only 2 to 5 years.
About 30,000 people in the U.S., and more than 200,000 worldwide, suffer from this debilitating disease. And universally, diagnosis is a shock: more than 90% of people living with ALS have no family history of the disease, and it can strike adults at nearly any age.
Amylyx Misleads the Market About Offering Unprecedented Hope for Addressing ALS
In October 2022, Amylyx—a biotechnology company developing treatment for ALS—commercially launched its flagship drug agent, Relyvrio, offering unprecedented hope for those suffering from ALS. Amylyx touted that “[Relyvrio] is the first drug candidate to show both a functional and survival benefit in a large-scale clinical trial.”
Typically, drugs that require approval from the Food and Drug Administration (“FDA”) must pass three challenging clinical trials, called “phases,” before they become commercially available. Due to the unmet need in the market for an effective ALS treatment, the FDA approved Relyvrio for commercial use while it was still undergoing its Phase III trial. The FDA approved Relyvrio in September 2022, and the drug went on the market the following month. The Phase III trial was to assess whether the drug was effective as compared to a placebo.
Given the devastating nature of ALS—and the lack of any viable treatment options—when Relyvrio was first launched, it was understood there would be an initial rush (or “bolus”) in demand and new patient subscriptions. Publicly, the defendants appeared to make good on the promise to help those with ALS. Throughout the launch, from October 2022 to over a year later, in November 2023, the defendants lauded the launch’s success and the near- and long-term ability for Relyvrio’s growth.
But as pled in the Amended Complaint, behind the scenes, the defendants failed to warn of an early, sharp decline in both new subscribers and patient discontinuations that would tank the posited hope for those suffering from ALS. Rather, the defendants were reporting the “net patient subscribers,” a metric that misleadingly omitted the high rate of discontinuations. For instance, at the peak “bolus” of demand around February and March 2023, a former employee revealed that there were 9,000 patients on Relyvrio. However, by May and August 2023, Defendants were reporting “net patients” on therapy at 3,000 and 3,800 respectively and assured the market that “strong demand” for therapy remained given 30,000 people suffer from ALS, and that it was still “too early to tell” the rate of discontinuation. Indeed, when asked about any discontinuations, the defendants responded that their metrics reported net patients on therapy, which they claimed was inclusive of any discontinuations, and that it was still a little early to identify long-term trends. In truth, as pled in the Amended Complaint, Relyvrio was causing significant side effects (including uncontrolled GI issues) while failing to manage or ameliorate the disease.
The truth began to emerge on November 9, 2023, when the defendants issued a press release reporting that a slowdown in new subscribers and an increase in discontinuations had resulted in a failure to meet anticipated Q3 2023 earnings. The defendants admitted that only 60% of patients remained in treatment after six months; corporate share value fell more than 30% in response to that news.
In March 2024, the defendants reported that the drug had failed to produce meaningful results in its Phase III trials, revealing that Relyvrio “failed to slow the progression of the disease,” and “made no significant difference versus a placebo in terms of helping patients perform daily living tasks such as walking and breathing.” The share price fell another 80% and, shortly thereafter, the Defendants announced that they would withdraw Relyvrio from the market.
Judge Gordon denied the defendants’ motion to dismiss, upholding May and August 2023 misstatements cited in the plaintiffs’ pleadings about the number of net patients on therapy, the rates of discontinuation, and growth opportunities for the drug.
This Court found that “plaintiffs have adequately alleged material misrepresentations with respect to forward-looking statements made in May and August 2023 that discuss growth opportunities within the ALS community.” As the Court reasoned, “[t]aking all well-pled factual allegations as true, 9,000 patients had been prescribed Relyvrio by the time of the peak of the bolus,” meaning that by the time Defendants were reporting on net subscribers in May and August, “more than 5,000 of the total 9,000 subscribers had discontinued treatment,” which “represents a discontinuation rate of over 50% and indicates that there was significantly less potential for new subscribers.” As such, “[t]he omission of this data could therefore be found to have rendered defendants' assertions regarding Relyvrio's growth potential materially misleading.”
Judge Gordon also concluded that the plaintiffs met the burden of pleading scienter. “Because the net subscriber metric was inclusive of all discontinuations, defendants would have been aware of those negative indications when calculating and reporting that metric.” Over the defendants’ objection, the Court credited the former employee’s statement that 9,000 patients were on the drug at the bolus given “the particular employee oversaw the company’s entire West Coast business operation and was responsible for 25% of the company’s revenue,” and “[i]t is plausible that such an employee would know what management knew with respect to the market status of their product.” The plaintiffs “also pled that defendants were tracking discontinuations in real time, which would establish that management had direct knowledge of the high number of discontinuations.” The plaintiffs continue pursuing recovery for Amylyx investors.