FDA Clears BioMarin’s Vimizim to Treat Rare Congenital Enzyme Disorder

The California-based BioMarin Pharmaceutical announced the U.S. Food and Drug Administration cleared its new drug Vimizim to treat a rare genetic disorder 'Mroquio A syndrome'.

Vimizim marketed by BioMarin, is the first drug to be approved by the federal agency to treat Mucopolysaccharidosis Type IVA: MPS IV-A (Morquio A syndrome), which is a rare inherited disease of metabolism caused due to the deficiency of N-acetylgalactosamine-6-sulfate sulfatase (GALNS).

This syndrome occurs due to a deficiency of certain enzymes needed to break the lengthy chains of sugar molecules known as glycosaminoglycans. Compared to MPS IV-A, the clinical features of MPS IV-B are fewer and milder. It causes symptoms like growth retardation, short neck, close knees, weakness of legs, prominent breast bone and flat feet.

According to FDA, there are over 800 people in the United States suffering with this rare genetic disorder. The newly approved drug is proposed to replace the missing GALNS enzyme that engages in a crucial metabolic pathway. 

This drug was granted  priority review by FDA. This is the first drug to receive the Rare Pediatric Disease Priority Review Voucher. By granting this provision FDA aims to encourage the development of novel drugs that help in treating and preventing very rare pediatric diseases.

"This approval and rare pediatric disease priority review voucher underscores the agency's commitment to making treatments available to patients with rare diseases," said Andrew E. Mulberg, M.D., deputy director, Division of Gastroenterology and Inborn Errors Products in the FDA's Center for Drug Evaluation and Research (CDER). "Prior to today's approval, patients with this rare disease have had no approved drug treatment options."

 In order to test the safety and effectiveness of Vimizim, a clinical trial was conducted on 176 subjects  with Morquio A syndrome of ages 5-57. The participants were randomly given either the new drug Vimizim or a placebo. After giving the drug the subjects were made to participate in a 6-minute walk test.  The safety and effectiveness of the drug was not established in pediatric patients less than 5 years of age.

The researchers observed that the subjects who were treated with Vimizim, showed  improvement in the walk test  compared to those given the placebo. Subjects who received Vimizim, on an average walked 22.5 meters farther in the 6 minute walk trial than those who received the placebo.

The common side effects caused by Vimizim include fever, vomiting, headache, nausea, abdominal pain, chills and fatigue. The drug carries a boxed warning mentioning the risk of anaphylaxis, as during the trial anaphylactic reactions occurred in a few subjects during Vimizim infusion.