In the latest setback for ALS research, Apellis Pharmaceuticals, a Massachusetts-based drug company, has discontinued a portion of a key clinical trial testing one of its medicines as a treatment for the nerve-destroying disease.
The “MERIDIAN” trial began in the fall of 2020, ultimately enrolling around 250 participants who were given either a placebo or Apellis’ medicine, known as pegcetacoplan, over one year. After 52 weeks, participants could join a so-called “open-label extension” phase, in which everyone would have access to the drug.
But Apellis has chosen to stop treatment in that latter phase based on feedback from an external group of advisers who reviewed the data available and concluded further treatment with the drug was unwarranted. Analysts at the investment bank Mizuho Securities were the first to report this development.
According to the analyst Graig Suvannavejh, Apellis announced the study discontinuation through a “company communication” that clarified that the decision was not due to any safety concerns.
“We plan to include this update in our quarterly earnings announcement and have disclosed the information to the individuals and organizations for whom it was most immediately relevant,” an Apellis spokesperson wrote in an emailed statement to BioPharma Dive.
The main portion of the trial has already been completed, and Apellis still plans to disclose in the middle of this year whether its drug met the primary goal by providing some level of benefit on function and survival. After that, the company intends to analyze the full data set to inform the next steps for its program.
The Mizuho team claims it wasn’t surprised by the Apellis update, as company leadership had previously called the main trial a “high risk, high reward study” with a low likelihood of success. Still, “the setback for pegcetacoplan may represent a negative development” for patients and drug developers targeting amyotrophic lateral sclerosis, Suvannavejh wrote in a note to clients Friday.
While the Food and Drug Administration recently approved a new medication for ALS, Amylyx Pharmaceuticals’ Relyvrio, and may clear another from Biogen later this month, the disease remains exceptionally difficult to treat. In the last two years alone, potential ALS therapies from Biogen, Cytokinetics, Alexion Pharmaceuticals and Biohaven Pharmaceuticals, among others, have all hit setbacks in important trials.
Apellis now joins that list.
Like the drug Alexion was testing, Apellis’ acts on the “complement system,” which is part of the body’s innate immune response. It specifically targets C3, a protein that, while integral in helping the body defend against pathogens, can also cause inflammation and even death of nervous system cells. According to Suvannavejh, ALS patients have high levels of activated C3.
Mizuho recently surveyed 35 ALS specialists and found that regulating the complement system is one approach that’s garnering more attention.
Additionally, pegcetacoplan has already proven effective at treating other rare disorders. The drug was initially approved by the FDA in 2021 under the brand name Empaveli for patients with a blood disease known as paroxysmal nocturnal hemoglobinuria.
Then, this February, an injectable version of the drug became the first ever medicine cleared in the U.S. for geographic atrophy, an eye illness that leads to vision loss.
Editor’s note: This story has been updated to clarify the period of time in which participants in MERIDIAN were randomized to receive either pegcetacoplan or placebo.