FDA delays BioMarin drug approval, gives investors hope

Data submitted by the company from studies did not persuade a panel of outside advisers to the FDA last month that the drug worked in DMD patients.

RBC Capital's Michael Yee thought the delay would not change the chances that the drug would be rejected. "Fundamentally it does not materially change the consensus view on Wall Street that nearly fully expects an FDA rejection and institutional buy-side expectations are remarkably very low after a very cautious or concerned panel in November," Yee said.

BioMarin's DMD drug, to be named Kyndrisa on getting the FDA nod, was expected to be the first treatment for the muscle wastage disorder that affects one in 3,600 newborn boys and causes rapid muscle degeneration.

At the panel discussion in November, 15 out of 17 members were of the opinion that the lack of statistical significance in BioMarin's late-stage study weakened the findings from two earlier studies.

FDA staff who pored over the company's data raised concerns about the drug, including potentially fatal long-term side effects such as kidney problems and reduction in blood platelets.

BioMarin's closest competitor Sarepta Therapeutics Inc's experimental DMD drug, eteplirsen, which works in similar way, is also expected to face a tough review by FDA staff and a panel of experts.