Orphan Medical Inc. failed to convince an FDA advisory committee last week that it has demonstrated the safety of its Xyrem gamma hydroxy butyrate (GHB) for the treatment of cataplexy, sudden loss of muscle tone in response to strong emotional reactions in narcolepsy patients. But the company says FDA is probably convinced.

COO William Houghton told BioCentury that the company started work on Xyrem in 1996 as a result of a suggestion from FDA's Office of Orphan Drugs, and "all development was planned absolutely in conjunction with the FDA." Despite this collaboration, significant differences between FDA's and ORPH's understanding of the path to approval have emerged over the last few months.