SAN RAFAEL -- Investors in BioMarin Pharmaceutical (Nasdaq: BRMN) have been bullish about the recent U.S. Food and Drug Administration approval for Vimizim, the first approved treatment for the rare disease Morquio A syndrome.

The price of shares jumped by more than 5 percent Thursday, closing at $80.13 per share. At $82.07 at the final bell Monday, the price was nearly 7.5 percent higher than it was Wednesday.

There are approximately 800 patients with Morquio A syndrome in the U.S.

Vimizim was granted priority review, according to BioMarin. An FDA priority review 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.

"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, MD, 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."

The safety and effectiveness of Vimizim were established in a clinical trial involving 176 participants with Morquio A syndrome, ranging in age from 5 to 57 years. Participants treated with Vimizim showed greater improvement in a 6-minute walk test than participants treated with placebo. On average, patients treated with Vimizim in the trial walked 22.5 meters farther in 6 minutes compared to the patients who received placebo.

BioMarin is set to report its fourth-quarter and 2013 financial performance on March 3.