The U.S. Food and Drug Administration has granted accelerated approval to Qalsody, also known as tofersen, marking the first treatment approved for a rare genetic form of amyotrophic lateral sclerosis. The decision applies to patients with ALS linked to a mutation in the SOD1 gene.

The approval gives doctors a new option for a disease that has long had few targeted therapies. ALS is a progressive neurological disorder that damages nerve cells controlling muscle movement, eventually affecting mobility, speech, swallowing and breathing.

Regulators said the authorization was based on data supporting the drug’s ability to address the underlying genetic cause in this subgroup of patients. Accelerated approval is typically used when a medicine shows promise for a serious condition but still requires additional evidence to confirm long-term clinical benefit.

For families facing SOD1-related ALS, the decision represents an important step in a field where treatment choices have been extremely limited. It also reflects continued progress in precision medicine, where therapies are designed around specific mutations rather than broader disease categories.