FDA Clears the First Drug for Rare Morquio A Syndrome

Megan Brooks

February 14, 2014

The US Food and Drug Administration (FDA) today approved the first drug for mucopolysaccharidosis type IVA (Morquio A Syndrome), a rare, autosomal recessive lysosomal storage disease caused by a deficiency in N-acetylgalactosamine-6-sulfate sulfatase (GALNS).

The drug elosulfase alfa (Vimizim, BioMarin Pharmaceuticals) replaces the missing GALNS enzyme involved in metabolism. Absence of this enzyme leads to problems with bone development, growth, and mobility.

There are approximately 800 patients with Morquio A Syndrome in the United States, according to the FDA.

In November 2013, an FDA advisory panel recommended in favor of approval of elosulfase alfa for Morquio A Syndrome.

The safety and efficacy of elosulfase alfa were demonstrated in a clinical trial involving 176 participants aged 5 to 57 years with the syndrome.

Compared with placebo, elosulfase alfa treatment was associated with greater improvement in a 6-minute walk test. On average, patients treated with elosulfase alfa in the trial walked 22.5 m farther in 6 minutes compared with patients given placebo.

The most common adverse effects seen with elosulfase alfa in clinical trials include fever, vomiting, headache, nausea, abdominal pain, chills, and fatigue.

"The safety and effectiveness of Vimizim have not been established in pediatric patients less than 5 years of age. Vimizim is being approved with a boxed warning to include the risk of anaphylaxis. During clinical trials, life-threatening anaphylactic reactions occurred in some patients during Vimizim infusions," the FDA notes in a statement.

Vimizim was granted priority review, which provides for an expedited review of drugs for serious diseases or conditions that may offer major advances in treatment.

"Vimizim is also the first drug to receive the Rare Pediatric Disease Priority Review Voucher — a provision that aims to encourage development of new drugs and biologics for the prevention and treatment of rare pediatric diseases," the FDA said.

"This approval and rare pediatric disease priority review voucher underscores the agency's commitment to making treatments available to patients with rare diseases," Andrew E. Mulberg, MD, deputy director, Division of Gastroenterology and Inborn Errors Products in the FDA's Center for Drug Evaluation and Research, said in the statement.


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