Lyrica (pregabalin) failed in two separate human trials to reduce neuropathic pain linked to diabetes or HIV, said makers Pfizer today. One of the trials – Phase III HIV neuropathy – was stopped early because no benefits were found in an interim analysis on 246 patients out of a planned 416.

The other study, also a placebo-controlled Phase III trial, involving 665 individuals, looked at Lyrica for peripheral diabetic neuropathy (second-line therapy). Other treatments had been ineffective.

The participants were switched to pregabalin (single-blind) for a period of six, and then randomly selected to be administered either more pregabalin or placebo for a further 13 weeks (double blind).

The patients on pregabalin did improve from baseline to the end of the trial period. However, there was not a significant difference when compared to the placebo – on a standard 10-point scale the difference was 3.9 versus 3.5.

Pregabalin is approved as first-line treatment for diabetic neuropathy, fibromyalgia, partial onset seizures, and postherpetic neuralgia.

Steven J. Romano, M.D., senior vice president, Head, Medicines Development Group, Global Primary Care Business Unit, Pfizer Inc., said:

“The results of this study show the complexities of studying pain, particularly in a difficult-to-treat condition such as neuropathic pain associated with HIV neuropathy for which there are no approved medications in the United States.

The study of Lyrica for this condition is an example of Pfizer’s dedication to better understanding neuropathic pain and to providing data and developing treatments to address areas of patient need.”

Neuropathic pain is chronic pain caused by a nervous system injury. The injury may be in the brain or spinal cord (central nervous system) or nerves outside the spinal cord or brain (peripheral nervous system).

Neuropathic pain can be the result of trauma and many diseases, such as multiple sclerosis, diabetes, HIV, and stroke.

Neuropathic pain affects approximately 2 million people in the USA. It is often very hard to treat properly.

Written by Christian Nordqvist