List of products in the National Drug Code with proprietary name . Galsulfase is used to treat a certain rare genetic problem (Maroteaux-Lamy syndrome - MLS). Galsulfase replaces a certain natural substance that is missing in people with MLS. This medication improves how far you can walk and the number of stairs you can climb up. Galsulfase does not correct the genetic problem, and treatment must be continued for life.