By Toni Clarke
(Reuters) – PTC Therapeutics Inc’s experimental drug to treat Duchenne muscular dystrophy, a devastating degenerative disease that mostly affects young boys, may work but the company will need to do more work to prove it, an advisory panel to the U.S. Food and Drug Administration concluded on Thursday.
The panel’s vote reduces the chance the drug will be approved soon since the FDA generally follows the advice of its advisors. Even so, the vote could have been worse for PTC. The panel could have rejected the drug outright, which in turn could have imperiled European sales of the product.
In Europe the drug is approved on a conditional basis, meaning approval must be renewed every year. It could win full European approval if data definitively proving effectiveness is submitted during the conditional period.
FDA scientists argued strongly that the company had failed to prove that the drug works. More fundamentally, said Dr. Billy Dunn, director of neurology products at the FDA, the company had sliced and diced data to try to extract a positive result, making the entire data set untrustworthy.
“We are not arguing about the numbers,” Dunn said. “Our concern is much more fundamental and concerns the basis of the scientific method.”
Panelists tended to agree. Ten out of 11 voted that the data were inconclusive.
Dr. Aaron Kesselheim, Associate Professor of Medicine at Harvard Medical School, said he was concerned about the possibility that the way the data was analyzed could be misleading.
Duchenne muscular dystrophy (DMD) starts in childhood and mainly affects males. More than 90 percent of patients become wheelchair-bound by the age of 15. There is no cure.
PTC argued that the FDA has the flexibility to approve the drug, even though it failed to meet the goal of multiple clinical trials. It noted that ataluren increased the production of dystrophin, a protein needed for muscle development.
Earlier this year Dr. Janet Woodcock, head of the FDA’s pharmaceuticals…