Survival benefit seen for patients with ALS drug CNM-Au8: New data
Clene planning to seek therapy's accelerated approval from FDA in early 2026
- New FDA-requested analyses show CNM-Au8 reduced biomarkers of nerve damage in ALS patients.
- Biomarker reductions were associated with improved survival outcomes in people with ALS.
- Developer Clene plans to seek therapy's accelerated approval from FDA in early 2026.
Clene is planning to submit an application to the U.S. Food and Drug Administration (FDA) in early 2026 requesting accelerated approval of its oral therapy CNM-Au8 for treating amyotrophic lateral sclerosis (ALS).
The company’s announcement follows new, positive data — from FDA-requested analyses — showing that CNM-Au8 consistently reduces blood biomarkers of nerve damage, and that these reductions are strongly associated with better survival outcomes.
The findings, from the HEALEY ALS platform trial (NCT04297683) and an expanded access program, strengthen Clene’s case for accelerated approval — a pathway that enables the FDA to conditionally approve a therapy based on early clinical data suggesting it’s reasonably likely to benefit patients. The regulatory agency had sought the analyses at a meeting with Clene last year, which set forth a path for the therapy’s potential approval.
If conditional approval is granted, a long-term decision on the therapy would depend on results from additional studies confirming that CNM-Au8 actually benefits patients. A Phase 3 trial called RESTORE-ALS is being planned to serve as that confirmatory study, Clene noted in a company press release.
“We followed the FDA’s roadmap — and the data delivered,” said Rob Etherington, president and CEO of Clene. “This is a remarkably consistent dataset that makes a strong case for accelerated approval.”
Clene has requested a meeting with the FDA to present the full results, which it expects will take place in the first quarter of next year. A formal application for accelerated approval is anticipated soon afterward.
“We look forward to presenting these analyses to the division in the requested type C meeting in the first quarter of 2026 and working with the FDA toward an NDA [new drug application] submission for accelerated approval,” Etherington said.
ALS is marked by the degeneration and death of motor neurons, the nerve cells that control voluntary movement. CNM-Au8 is a gold nanoparticle formulation that’s designed to boost energy production in nerve cells, which aims to improve the survival and function of motor neurons.
The therapy was previously tested in an arm (NCT04414345) of the HEALEY trial, which is assessing several experimental ALS treatments simultaneously.
Although the study failed to meet its main goal of showing that CNM-Au8 slowed a functional decline relative to a placebo, data indicated that the 30 mg dose reduced the risk of death and slowed disease progression. Long-term data from an open-label extension also showed a consistent survival benefit.
Data from HEALEY also indicated that CNM-Au8 treatment reduced levels of neurofilament light chain (NfL), a marker of nerve damage. Clene is planning to base its application for accelerated approval largely on these biomarker data, per the release.
FDA had requested 3 analyses of the effects of CNM-Au8
At the meeting last year, the FDA asked Clene to complete three specific analyses to further evaluate the effects of CNM-Au8 in ALS.
The first analysis involved examining levels of NfL in an expanded access program funded by the National Institutes of Health (NIH). According to Clene, CNM-Au8 treatment in this program resulted in reductions in NfL similar to those observed in the HEALEY trial.
The second analysis focused on another marker called glial fibrillary acidic protein (GFAP), whose levels reflect damage to astrocytes, which are star-shaped cells that help support motor neurons. Clene now reported that CNM-Au8 reduced GFAP levels in both the HEALEY trial and the expanded access program, and that this biomarker followed a pattern similar to NfL.
The consistency of [biomarker] reductions in more advanced patients treated in the expanded access program is particularly compelling and suggests potential disease-modifying activity of CNM-Au8.
The company also noted that patients with the greatest decreases in NfL and GFAP tended to have the longest survival times.
“The consistency of NfL and GFAP reductions in more advanced patients treated in the expanded access program is particularly compelling and suggests potential disease-modifying activity of CNM-Au8,” said Jinsy Andrews, MD, principal investigator of the NIH-sponsored expanded access program. Andrews also serves as the director of the Amyotrophic Lateral Sclerosis Center and medical director of clinical trials at NYU Grossman School of Medicine in New York.
The third analysis examined data from people who initially received a placebo in HEALEY but later switched to CNM-Au8 during the trial’s open-label extension. Among the 31 patients with available data, NfL levels tended to stabilize or decline after switching to CNM-Au8. While the small sample size limits firm conclusions, the company said the declines were similar to those observed in the CNM-Au8 group during the main trial.
In addition to the analyses outlined in the FDA’s roadmap, Clene also shared updated survival data from the HEALEY trial and its extension period. According to the latest analyses, CNM-Au8 has significantly reduced the risk of death after one year by more than 70%.
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