Results from the trial, which involved 407 postherpetic neuralgia (PHN) patients, did not demonstrate statistically significant efficacy relative to placebo in patients receiving an 1800mg total daily dose of gabapentin GR given once or twice-daily.
The primary endpoint of the study was to assess the efficacy of gabapentin GR compared to placebo in reducing average daily pain scores from baseline to endpoint.
The primary endpoint was not achieved with statistical significance for either active treatment regimen, as compared to placebo, over the ten-week treatment period of the trial.
“The Phase III results we received today were very surprising and disappointing to us in light of the encouraging safety and efficacy data that we observed in our Phase II clinical trial, in which we achieved statistically significant results in a four-week period as compared to placebo,” said John Fara, chairman, president and CEO of Depomed.
Gabapentin GR is an investigational extended release and gastric retained form of gabapentin, an FDA-approved Pfizer product for the treatment of PHN.