(Reuters) – Privately held drug developer Amylyx Pharmaceuticals Inc said on Tuesday its experimental therapy to treat amyotrophic lateral sclerosis (ALS) helped slow the progression of the fatal neurological disorder in a mid-stage study.

ALS, also known as Lou Gehrig’s disease, is a rare disorder that attacks nerve cells responsible for controlling voluntary muscles, and over 6,000 Americans are diagnosed with the disease every year, according to the ALS Association.

Patients on Amylyx’s therapy, AMX0035, had a longer retention of function than those on placebo, said Dr. Sabrina Paganoni, the principal investigator of the study.

As the brain’s ability to start and control voluntary movement is lost, the patient succumbs to the disease — usually within three to five years from the onset of symptoms.

There are only two treatments approved for the disorder. While neither treatment cures the disease, they help moderate the symptoms.

Amylyx said it will work with the U.S. Food and Drug Administration to determine the next steps for the therapy, and the company is expected to provide an update early next year.

(Reporting by Saumya Sibi Joseph in Bengaluru; Editing by Amy Caren Daniel)