The U.S. Food and Drug Administration has granted Ultragenyx Pharmaceutical, Inc. approval of MEPSEVII, a drug that treats an inherited metabolic condition called mucopolysaccharidosis type VII (MPS VII). Under 150 people worldwide are diagnosed with MPS VII, an extremely rare and progressive condition that affects most tissues and organs.

MPS VII is a lysosomal storage disorder caused by deficiency of an enzyme called beta-glucuronidase, which causes an abnormal buildup of toxic materials in the body’s cells. MEPSEVII works as an enzyme replacement therapy that replaces that missing enzyme.

Most patients with MPS VII have various skeletal abnormalities, including short stature. Affected individuals can also develop heart valve abnormalities, enlarged liver and spleen, and narrowed airways which can lead to lung infections and trouble breathing. Heart disease and airway obstruction are major causes of death for those suffering with the condition.

“This approval underscores the agency’s commitment to making treatments available to patients with rare diseases,” said Julie Beitz, M.D., director of the Office of Drug Evaluation III in the FDA’s Center for Drug Evaluation and Research. “Prior to today’s approval, patients with this rare, inherited condition had no approved treatment options.”