Pfizer’s Lyrica Phase 3 study on pDPN fails to meet primary endpoint

Pfizer Inc. (NYSE: PFE) announced today that a Phase 3 randomized withdrawal design study for Lyrica (pregabalin) in patients with inadequately treated painful diabetic peripheral neuropathy (pDPN) did not meet its primary efficacy endpoint, change in endpoint mean pain score relative to baseline. The study, A0081242, is a Phase 3b Multicenter, Double-Blind, Randomized Withdrawal Efficacy and Safety Study of Pregabalin in the Treatment of Patients with Inadequately Treated Painful Diabetic Peripheral Neuropathy.

Patients who had inadequate pain control while receiving a medication for pDPN were switched to Lyrica (150 or 300 mg/day) during a 6-week single-blind phase. Patients with ≥30% pain improvement were randomized to receive placebo or to continue treatment with Lyrica for the 13-week double-blind treatment phase.

665 patients received Lyrica in the single-blind phase of the study and had an improvement in single-blind endpoint mean pain score relative to baseline of 2.2 points (0-10 scale). Of the 294 patients who had ≥30% pain response and were randomized, Lyrica-treated patients had a total improvement in endpoint mean pain score of 3.9 points relative to baseline; however, this was not statistically significant compared to placebo (3.5 point total improvement). Further analyses will be conducted on these initial results.

The results for this study indicate that the most common adverse events in Lyrica-treated patients were peripheral edema, dizziness, somnolence and upper respiratory tract infection when compared with placebo. The adverse event profile is consistent with that known for Lyrica.