Sanofi now has the “only approved treatment for ASMD,” after Japan’s drug regulator cleared Zenpozyme for use in patients of all ages.

Also known as olipudase alfa, the drug is the first therapy for rare non-central nervous system (non-CNS) manifestations of acid sphingomyelinase deficiency (ASMD), the French drugmaker said.

ASMD is a genetic, progressive disease characterized by abnormal levels of the lipid sphingomyelin, which accumulates in cells, causing cell death and organ failure. Sanofi estimates that the disease impacts 2,000 people in the U.S., Europe and Japan.

The trial that led to the OK from Japan’s Ministry of Health, Labor and Welfare included 36 subjects in a phase 2/3 ASCEND trial that showed xenpozyme could help mitigate organ damage caused by the disease. Patients who received biweekly infusions of the drug saw improved lung function, as well as reduced spleen and liver volumes.

Looking ahead, the company is chasing approval in other countries. A Biologics License Application (BLA) for the drug was accepted for Priority Review by the U.S. FDA, with a decision expected later this year. In Europe, the EMA has awarded olipudase alfa the PRIority MEdicines (PRIME) designation.