FDA Grants Orphan Drug Status to Amylyx’s AMX0035 for Treatment of ALS

The U.S. Food and Drug Administration (FDA) granted orphan drug designation to AMX0035 for the treatment of amyotrophic lateral sclerosis (ALS), Amylyx Pharmaceuticals, the drug developer, announced in a press release.

Orphan drug status aims to encourage therapies for rare and serious diseases through incentives such as seven years of market exclusivity and exemption from FDA application fees. This will help Amylyx to continue the clinical development and evaluation of AMX0035.

AMX0035 consists of the combination of two small molecule compounds – sodium phenylbutyrate and tauroursodeoxycholic acid – which, at a specific dose ratio, inhibit mechanisms involved in cellular stress. Both compounds have been used in the clinic, with proof of being safe and well-tolerated.

Preclinical studies with AMX0035 in animal models of ALS, Alzheimer’s disease, and mitochondrial diseases showed that the drug combination can effectively inhibit nerve cell death and inflammation of nerve cells. In addition, the results suggest that use of the drugs in combination can result in improved effectiveness compared to the individual compounds alone.

Amylyx recently initiated the Phase 2 CENTAUR clinical study (NCT03127514) to assess the safety, tolerability, and efficacy of AMX0035 in ALS patients.

The placebo-controlled trial is being conducted in 25 clinical centers across the United States, and is expected to include 132 individuals with sporadic or familial ALS. Eligible participants cannot have received Rilutek (riluzole) for at least 30 days prior to the initial screening.

Patients will receive twice-daily administrations of AMX0035 or a placebo for 24 weeks, followed by four weeks of safety evaluation.

The researchers will evaluate the effects of the investigative drug on disease progression, determined by the revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R), over the duration of the study. The impact of AMX0035 on secondary outcome measures, including decline of muscle strength, respiratory function, and blood biomarkers of nerve cells death, will also be evaluated.

Amylyx is now planning an open label extension to the CENTAUR trial to allow all participants to continue AMX0035 treatment after the end of the 24-week treatment period.

Additional information about the CENTAUR trial, including information for possible participation, can be found on the study’s clinical trials.gov webpage under contacts and location.