IPX066, a Parkinson’s drug by Impax and Glaxo, achieved study goal

Earlier on Monday, Impax Laboratories Inc. and GlaxoSmithKline PLC declared that a late-stage study for IPX066, an extended-release investigative drug for Parkinson’s disease, achieved its primary endpoint. Parkinson’s is a degenerative sickness characterized by symptoms such as rigidity, tremors, and slow movements.

In morning trading, Impax shares hiked $1.83, or 10.9 percent, to $18.63.

IPX066 is a Parkinson’s disease treatment designed to be a longer-lasting version of a common treatment for the physical symptoms of the disease. The clinical trial compares the effectiveness of the new formulation IPX066 with the standard drugs levodopa and carbidopa.

According to Impax and GlaxoSmithKline, patients administered the drug demonstrated a considerable decrease in “off time,” or waking time, when the effect of drug faded and motor symptoms returned.
While patients consuming the new formulation demonstrated an average 3.8 hours of “off time” per day, those consuming the standard drugs levodopa and carbidopa averaged at 5.2 hours. Patients commenced the study with an average of 5.9 hours of “off time.”

Eighty-four patients completed the study, said Impax and GlaxoSmithKline. Insomnia, confusion, and sudden, uncontrollable muscle movements were some of the common side effects with IPX066 treatment, which were observed in three patients each. Two patients on the carbidopa-levodopa regimen were fraught with the most common side effect of falling.

Compared to 14% patients who were administered the standard drugs, 20% patients treated with IPX066 had side effects. While patients in the carbidopa-levodopa group showed no side effects, those in the IPX066 group demonstrated two serious side effects: sciatica and dehydration.

Carbidopa and levodopa are available as a combination drug under several brand names, one of those being Sinemet.
Three late-stage trials are being conducted by the companies for IPX066. In the fourth quarter, Hayward, Calif. based Impax is expected to apply for U.S. approval of the drug. The company also proposes to present complete results from the current study at a future scientific meeting.

London-based GSK will apply for European regulatory authority approval in 2012. Apart from the U.S. and Taiwan, GSK has complete rights to develop and market the drug in all countries.
GSK shares hiked 60 cents to $41.90