Plant problems stymie Impax NDA, FDA says

Drug development--Courtesy of Impax Laboratories

Plant problems don't always mean an interruption of production of existing product. Sometimes they can keep a new drug from potentially getting to market, Impax Pharmaceuticals ($IPXL) has found.

The company said Monday that in a complete response letter, the FDA "requires a satisfactory re-inspection of the company's Hayward facility as a result of the warning letter issued in May 2011" before it will approve Impax's NDA for an extended-release capsule formulation of carbidopa-levodopa, for the symptomatic treatment of Parkinson's disease.

The warning letter in May 2011 and then a follow-up inspection in February 2012 found that Impax appeared to have reported quality control data that was different from its trial samples taken of the Type 2 diabetes drug Acarbose. The manufacturing plant also was conducting "unofficial and undocumented investigations," to evaluate suspect QC data, according to the FDA. That included looking for product cross-contamination due to "unexpected peaks." While conducting undocumented investigations on one hand, it wasn't even looking into "unexpected manufacturing discrepancies," including critical equipment failures on the other, inspectors noted in the February visits.

The 2011 warning followed a wholesale-level recall of 5 lots of 200 mg fenofibrate capsules. The recall of the high-cholesterol treatment was prompted by the problems inspectors found during their visits. Impax had to temporarily reduce production to make quality assurance changes and it brought in some experts to help with fixes.

The Impax facility in Taiwan--Courtesy of Impax Laboratories

Impax specializes in extended release formulations and Rytary is an investigational extended-release capsule formulation of carbidopa-levodopa for the treatment of idiopathic Parkinson's disease. In its second-quarter earnings report last year, the company said the FDA had found no problems at its Taiwan plant during a "preapproval inspection for Rytary" but that the FDA would have to do a re-inspection at the Hayward, CA, plant before that plant would be cleared. In its announcement Monday, the company said it had withdrawn the Hayward site as an alternative for the commercial launch. Impax CEO Larry Hsu said, "We will work with the FDA on the appropriate next steps for the Rytary application. We remain committed to resolving the warning letter and bringing this new treatment option to patients."

- read the release
- here's the warning letter