A drug currently used to treat fibromyalgia and other chronic pain disorders is not effective in reducing neuropathic pain caused by HIV infection or diabetes, according to the drug’s manufacturer.
Pfizer ordered a halt to two phase III studies after preliminary results showed that pregabalin, which is sold under the brand name Lyrica, was no more effective than a placebo.
In the HIV neuropathy study, an interim analysis was conducted after 246 patients were given either Lyrica or a placebo.
“The results revealed that the improvements in neuropathic pain symptoms in this study were virtually identical between the Lyrica and placebo treatments,” Pfizer said in a statement. The drug maker said no safety issues were raised.
The other phase III study evaluated Lyrica as therapy for 665 patients who had not responded to earlier treatment for peripheral diabetic neuropathy. All patients were given Lyrica for 6 weeks and then switched to either a placebo or continued using Lyrica for 13 weeks.
Pfizer said that patients who took Lyrica continued to show improvements, but they were not significantly different from those seen in the placebo group. Side effects from taking Lyrica included peripheral edema, dizziness, somnolence and upper respiratory tract infection. The symptoms are consistent with what is already known for Lyrica.
Pfizer said further analysis will be conducted on the initial results from the two studies. Lyrica is already approved in the U.S.for treatment of diabetic peripheral neuropathy, a form of nerve damage characterized by burning pain, pins and needles, or shooting pain in the feet and hands. About 20% of people with diabetes experience pain from nerve damage.
Lyrica was the first medication approved by the Food and Drug Administration for the treatment of fibromyalgia. The drug is also used to treat pain from shingles and seizures in adults with epilepsy.