GSK/Xenoport drug fails Ph II DPN study

UK drug major GlaxoSmithKline and USA-based XenoPort reported data showing that gabapentin enacarbil missed its primary endpoint in a  mid-stage trial in neuropathic pain associated with diabetic peripheral  neuropathy.

The agent did not demonstrate a statistically-significant improvement  when compared to placebo, based on the change from baseline to end of  treatment on the Pain Intensity-Numerical Rating Scale. The pregabalin  active control arm also did not differentiate from placebo on this same  endpoint. The failure of the study to demonstrate a  statistically-significant benefit on the primary endpoint may be a  consequence of the unexpectedly high placebo response rate observed in  the study, the firms noted.

"We will be evaluating the study results further in order to determine  our next steps," said Atul Pande, senior vice president, GSK  Neurosciences Medicines Development Center. Ronald Barrett, chief  executive officer of XenoPort, added that "a high placebo response is  not uncommon in DPN studies, and this has been a contributing factor to  several failed studies testing different drugs in these patients."