Rx for Rare Genetic Disorder Gets FDA Green Light

Mepsevii (vestronidase alfa-vjbk) approved to treat patients with Sly syndrome

(RxWiki News) The US Food and Drug Administration (FDA) has approved the first treatment for a rare genetic disorder.

The FDA approved Mepsevii (vestronidase alfa-vjbk) to treat patients with mucopolysaccharidosis type VII (MPS VII). This disorder is also referred to as Sly syndrome.

MPS VII is a rare disorder that produces various symptoms, including skeletal, heart valve, liver, spleen and airway abnormalities. This disorder can drastically reduce life span. In addition, individuals with Sly syndrome may have intellectual disabilities and delays in development. The FDA noted that fewer than 150 patients around the world are thought to have this disorder.

“This approval underscores the agency’s commitment to making treatments available to patients with rare diseases,” said Dr. Julie Beitz, director of the FDA's Office of Drug Evaluation III, in a press release. “Prior to today’s approval, patients with this rare, inherited condition had no approved treatment options.”

MPS VII occurs because patients have too little of a particular enzyme. According to the FDA, Mepsevii replaces that enzyme.

In a clinical trial of 23 patients were given this medication. Ten patients, who could perform the test, showed improved mobility and two patients had improved lung function. Side effects included severe allergic reactions, rashes, diarrhea and infusion-site reactions. This medication holds a boxed warning in regards to the risk for anaphylaxis which requires immediate medical attention. 

The long-term safety of this medication will continue to be observed, according to the FDA.

Ultragenyx Pharmaceutical, Inc., manufactures Mepsevii.

Review Date: 
November 18, 2017