GSK and Impax announce positive topline results of ASCEND-PD Phase III study

The FINANCIAL — GlaxoSmithKline (GSK) and Impax Pharmaceuticals, the branded products division of Impax Laboratories, Inc. today announced top-line results of the ASCEND-PD Phase III clinical study of IPX066 versus carbidopa-levodopa plus entacapone (CLE), in patients with advanced Parkinson’s disease (PD).

IPX066 is an extended release capsule formulation of carbidopa-levodopa (CD-LD) under investigation for the treatment of the motor symptoms of PD.

The primary endpoint of this double blind crossover study was the percentage of “off time” during waking hours as measured by patient diary. “Off time” is the functional state when patients’ medication effect has worn off and there is a return of the motor symptoms of PD.  Patients entered the study with a baseline “off time” of 36.1% (5.9 hours), and at the end of the randomized IPX066 treatment phase patients had “off time” of 24.0% (3.8 hours) during waking hours compared to 32.5% (5.2 hours) for CLE (p<0.0001). This represents a 33.5% decrease in percent “off time” for IPX066 from baseline vs. a 10% decrease for CLE.

“Impax Pharmaceuticals and GSK are excited to report these positive results for the ASCEND-PD trial which demonstrate an 84 minute improvement in “off time” over CLE therapy with a corresponding increase in “on time” without troublesome dyskinesia," stated Dr. Suneel Gupta, Impax Pharmaceuticals' chief scientific officer. "Consistent with our earlier ADVANCE-PD Phase III study findings, this study also demonstrates that IPX066 provides efficacy across a range of clinically meaningful measures in advanced PD.  We are also pleased that the secondary endpoints supported the conclusion from the primary endpoint.”

During the double blind crossover period of this trial the adverse event (AE) rate for IPX066 was 20% compared to 14% for CLE. After randomisation two serious treatment-emergent adverse events were reported with both occurring on IPX066 therapy (sciatica and dehydration) and none on CLE. The most common AEs reported for IPX066 included: insomnia, confusional state, and dyskinesia (each event was reported by 3 subjects). The most common AE reported for CLE was: fall (reported by 2 patients on CLE).

Impax plans to submit these data as part of its New Drug Application (NDA) for IPX066 to the FDA, which is planned for the fourth quarter of 2011.  GSK plans to file the Marketing Authorisation Application for IPX066 in the European Union in 2012.