A new drug, Qalsody (tofersen), has won approval for treating amyotrophic lateral sclerosis (ALS), a severe, rare disease characterized by muscle weakness and progressive loss of motor function, commonly known as Lou Gehrig's disease.

The Ministry of Food and Drug Safety (MFDS) announced on Wednesday that it had approved Qalsody, designating it as the 31st product under the Global Innovative Product Fast-Track (GIFT) review support system for marketing.

Qalsody is a nucleic acid therapy that binds to SOD1 mRNA in patients with ALS caused by SOD1 gene mutations, reducing the synthesis of mutated SOD1 proteins.

SOD1 is an antioxidant protein that acts as an enzyme to protect neurons from damage caused by reactive oxygen species. Mutations in this gene can cause ALS.

“We expect this to provide new treatment opportunities for adult patients with ALS caused by SOD1 gene mutations, for whom there are currently no appropriate treatments,” the ministry said. “We will continue to do our best to swiftly review and approve treatments with sufficient safety and efficacy based on our regulatory science expertise, thereby expanding treatment opportunities for patients.”