Pfizer Inc. has announced 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. This follows an announcement regarding the failure of the drug to help patients with neuropathic pain associated with HIV neuropathy in a Phase 3 study and the stopping of the study.
In the Lyrica study, 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 equal to or greater than 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 equal to or greater than 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.
Painful diabetic peripheral neuropathy is a form of nerve damage characterized by burning pain, pins and needles, or shooting pain in the feet and often in the hands as well. About 20 percent of people with diabetes experience pain resulting from nerve damage.
Lyrica is currently approved in 110 countries and regions globally. In the United States, Lyrica (pregabalin) capsules CV is approved for the management of neuropathic pain associated with diabetic peripheral neuropathy.