FDA Approves Metabolism Disorder Drug, Marks End of Pediatric Priority Review Program

The FDA approved Asklepion Pharmaceuticals’ Cholbam, the first treatment for children and adults with single-enzyme bile acid disorders and peroxisomal disorders, under its pediatric rare disease priority review voucher program. Under the terms Congress set for the program, the FDA must now phase it out within 12 months unless it is reauthorized.

Drugs approved under the pediatric review program win seven years of marketing exclusivity granted to orphan drugs and a priority review voucher that can be used for any other drug to give it accelerated FDA review.

After last week’s approval, Asklepion will transfer both the voucher and the drug to San Diego-based Retrophin, which is acquiring the rights to Cholbam (cholic acid) and plans to market it as soon as next month.

Under the special pediatric review program, the FDA was allowed to approve three drugs; after that, it can approve more drugs through the program, but only through March 17, 2016. At that point, the agency must halt the program while the GAO reviews it and Congress decides whether to extend it.

The first approval under the program went to Biomarin in February of last year for its Morquio A Syndrome therapy Vimizim (elosulfase alfa). United Therapeutics nabbed the second voucher last week upon approval of Unituxin (dinutuximab) for neuroblastoma.

Asklepion tested Cholbam in an uncontrolled trial of 50 patients with bile acid synthesis disorders over a period of 18 years. Roughly 64 percent of patients gained weight with improved liver function and two-thirds lived more than three years. Patients with peroxisomal disorders did better, with 42 percent of the 29 patients surviving more than three years.

The FDA is asking for a long-term postmarket observational study to assess the drug’s safety. — Lena Freund