Impax announces positive top-line results of Phase III IPX066 study for Parkinson's disease

Impax Pharmaceuticals, the brand products division of Impax Laboratories, Inc. (NASDAQ: IPXL), today announced positive top-line results of the APEX-PD Phase III clinical study with IPX066 in Parkinson's disease (PD). IPX066 is a novel extended release carbidopa-levodopa product. The APEX-PD results demonstrate that IPX066 is safe and efficacious when used in patients with early Parkinson's disease.

“We are thrilled to report these positive results of the APEX-PD trial demonstrating robust efficacy in early Parkinson's disease across a range of objective and subjective measures for each of the doses tested”

The trial met its primary efficacy endpoint of change from baseline in the sum of Unified Parkinson's Disease Rating Scale (UPDRS) Parts II and III score at end of study. The UPDRS Part II measures the activities of daily living and the UPDRS Part III measures motor symptoms of PD. All three doses of IPX066 showed significant improvement compared to placebo (p<0.0001 for all treatments). The mean sum of Parts II and III UPDRS score on IPX066 treatment improved 13.2 units (36%) compared to an improvement of 0.6 units (2%) with placebo treatment, indicating a major improvement in PD symptom severity in early PD patients as a result of IPX066 treatment.

"We are thrilled to report these positive results of the APEX-PD trial demonstrating robust efficacy in early Parkinson's disease across a range of objective and subjective measures for each of the doses tested," stated Dr. Suneel Gupta, Chief Scientific Officer of Impax Pharmaceuticals. "We are working diligently to complete the clinical trial program on schedule and target a New Drug Application (NDA) filing by the end of 2011."

Consistent with the results observed in the UPDRS, IPX066 also demonstrated mean improvements of 72% in both Clinician Global Impression of change (CGI) and Patient Global Impression of change (PGI) compared to improvements of 27% and 34% for placebo in CGI and PGI, respectively (p<0.0001 for both measures at all three dose levels). In addition, IPX066 treatment resulted in an improvement over placebo in quality of life as measured by the Parkinson's Disease Questionnaire (PDQ-39) at week 30 (p<0.02).

The most commonly reported adverse events in the IPX066 treatment arms included nausea, headache, and dizziness which are consistent with carbidopa-levodopa products. The proportion of subjects experiencing adverse events was similar for IPX066 and placebo treated subjects (69% compared to 73%, respectively). No unexpected drug-related serious adverse events were observed in IPX066 treated subjects.

Impax Pharmaceuticals plans to present complete results of the APEX-PD study at an upcoming scientific meeting.

The APEX-PD study was a randomized, double-blind, placebo controlled, parallel group, fixed-dose study comparing 3 doses of IPX066 to placebo in patients with early Parkinson's disease. The study was conducted under a Special Protocol Assessment agreement with the US Food and Drug Administration (FDA) and is part of the IPX066 clinical development plan agreed with the FDA and the European Medicines Agency.