Raptor Pharmaceutical ($RPTP) has scored an FDA approval of its new drug for a rare metabolic disorder. But the steep, 6-figure price tag being put on the drug, Procysbi, is already drawing flak from a growing contingent of analysts who wonders just how much drug developers can command from payers for rare-disease drugs before a backlash occurs.
Raptor's Procysbi is a me-better drug, a delayed-release version of cysteamine, which Mylan sells as Cystagon. This new version allows patients to avoid some of the GI side effects of the older therapeutic, which also requires more frequent dosing. Bloomberg estimated annual U.S. sales of about $75 million.
"Procysbi is the only delayed-release product approved by FDA to treat nephropathic cystinosis, offering patients with this rare disease an important new treatment option," said Dr. Andrew E. Mulberg, deputy director of the Division of Gastroenterology and Inborn Errors Products at FDA's CDER. There are only some 500 patients with this condition in the U.S., while the estimated global population is about 3,000.
Rare disease drugs are all the rage in biopharma these days, as developers focus on small populations of patients demanding life-saving therapies. But Raptor may soon test payers' appetite for orphan therapies. As Adam Feuerstein notes in The Street, the price for the new drug is $250,000 a year, a 2,400% markup over the $10,000 annual cost of Mylan's much older drug. And The New York Times' Andrew Pollack raises the same question in his coverage of the approval.
But one of the experts in the field says that the demand should be strong among the limited group.
"In addition to providing sustained control of cystine levels, Procysbi's dosing schedule and side effect profile may help patients stay the course with their treatment," says Craig Langman, a physician at the Ann & Robert H. Lurie Children's Hospital of Chicago, in the statement from Raptor. "The fact that 40 of 41 patients from the Phase III trial elected to enroll in the extension study and have been followed for two years now demonstrates their motivation to be on Procysbi therapy."
Raptor gained a $25 million advance under its $50 million loan agreement with HealthCare Royalty Partners on the approval.