Clene Reports Improved Long-Term Survival for ALS Patients Treated with Drug Candidate

Pictured: Clene CEO Rob Etherington/company courtesy

Pictured: Clene CEO Rob Etherington/company courtesy

Utah-based biopharma company Clene reported promising results on Monday for its experimental amyotrophic lateral sclerosis drug based on long-term, follow-up survival data from the HEALEY ALS Platform Trial.

The trial of 59 participants showed that Clene’s CNM-Au8, given in 30 mg doses, reduced the risk of death in patients with amyotrophic lateral sclerosis (ALS) by 49% with “no serious adverse events” associated with the therapy.

The experimental treatment is an oral suspension of gold nanocrystals, the surfaces of which catalyze oxidation-reduction reactions, which could help ameliorate cellular energy deficits and oxidative stress that are associated with neurodegenerative conditions like ALS.

Benjamin Greenberg, head of medical at Clene, said in a statement that the “consistent long-term survival data” from the HEALEY ALS Platform Trial—along with a “continued clean safety profile”—adds to the “totality of the survival evidence.”

The Healey ALS Platform Trial is somewhat unusual in structure. Patients were enrolled in summer 2020 and received CNM-Au8 in addition to standard-of-care treatment and were randomized to receive either the treatment or a placebo during the 24-week double-blind period.

However, rather than compare patient groups receiving either the treatment or a placebo within this trial against one another, they compared the treatment recipients against placebo recipients in the PRO-ACT database. It is the largest U.S. database of previous ALS trials, composed of pooled data from 29 Phase II and III trials, representing millions of records from nearly 12,000 participants.

“This database provides a useful and validated surrogate for survival status of past participants in ALS clinical trials with long-term follow-up,” Clene said in Monday’s announcement.

The company also noted that the only “adverse events observed with CNM-Au8 have been characterized as transient and predominantly mild-to-moderate in severity.”

Monday’s news follows mostly positive but somewhat mixed results recently for Clene. The company announced promising results in June 2023 for the therapy in reducing plasma neurofilament light chain concentrations. Crucially, this reduction was present in multiple high-risk subpopulations, including those at risk of fast disease progression, with definite or probably ALS diagnosis, or those at greater risk of death.

In March 2023, Clene announced evidence that the treatment delayed disease progression across all domains. The news came as a positive development after the treatment failed to meet its primary endpoint of slope of change in October 2022. However, strong survival signals noted at the time suggested there may be more to the story.

That evidence included a 74% reduction in composite endpoint of time to ALS clinical worsening, 98% reduction in risk of death or permanent ventilation, 74% reduced risk of feeding tube placement, and 84% decreased risk of ALS-related hospitalization.

Clene has been gathering the biomarker data “for FDA regulatory discussion in the third quarter [of 2023],” CEO Rob Etherington said in June 2023, after the FDA indicated that was a viable path to regulatory authorization in April when it approved Biogen and Ionis’ tofersen—marketed as Qalsedy—on that basis. He also noted at the time that the company “is exploring the possibility for (sic) a [New Drug Application] filing.”

Connor Lynch is a freelance writer based in Ottawa, Canada. Reach him at

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