FDA stiff-arms Impax on extended-release Parkinson's combo

The FDA has thrown up a roadblock for Impax Laboratories' ($IPXL) extended-release version of a carbidopa-levodopa combo for Parkinson's disease now dubbed Rytary. The agency issued one of its complete response letters, according to Impax, pointing to a manufacturing issue that will have to be cleared up ahead of any formal decision on marketing the treatment

The complete response letter indicates that the FDA requires a satisfactory reinspection of the company's Hayward facility as a result of the warning letter issued in May 2011 before the company's NDA may be approved due to the facility's involvement in the development of Rytary, noted Impax. GlaxoSmithKline ($GSK) licensed the ex-U.S. rights to Rytary.

"We will work with the FDA on the appropriate next steps for the Rytary application," said Larry Hsu, Ph.D., president and CEO, Impax Laboratories. "We remain committed to resolving the warning letter and bringing this new treatment option to patients who are suffering from Parkinson's disease."

Piper Jaffray analyst David Amsellem told Bloomberg that a sustained-release form of the standard Parkinson's therapies has been difficult to get past regulators. And if Impax succeeds at the task, it will open the door to a market worth $200 million to $300 million a year. Most new patients likely to be steered to this new combo treatment would have failed the standard remedies available.

Investors appeared only slightly frustrated by the delay, pushing Impax shares down about 8% by late morning today.

- here's the release
- here's the story from Bloomberg