by Susan Jeffrey, 13 Oct 2006
Results of a multicenter, randomized trial of a still-investigational anticonvulsant drug, lacosamide, suggests the drug is both most efficacious and well tolerated at a dose of 400 mg/day over an 18-week period.
The new drug offers another potential alternative for treatment of this painful condition, where no single drug appears to work for all patients, coauthor James P. Wymer, MD, PhD, from Upstate Clinical Research in Albany, New York, told Medscape.
"We've got some very good drugs out there that have shown efficacy or have the FDA approval" for this indication, Dr. Wymer said, including gabapentin, pregabalin, and duloxetine. However, he noted, "I have a subset of patients who've done very well with lacosamide who haven't responded to other drugs. It's another drug to control this, and that's what we need."
The study, sponsored by Schwarz Biosciences and presented by Dr. Wymer on behalf of the SP742 Study Group, was presented here at the American Neurological Association 131st Annual Meeting.
Lacosamide is a novel anticonvulsant under investigation in both antiepileptic and pain-relief indications. As is the case with most newer anticonvulsants, its precise mechanism of action is not known, he said.
"This is the first of 2 phase 3 studies looking at how it works in painful diabetic neuropathy," Dr. Wymer said.
A total of 370 patients with moderate to severe pain, defined as a score of 4 or greater on the 11-point Likert Scale, were randomized to receive either placebo or 1 of 3 doses of lacosamide: 200, 400, or 600 mg/day. Patients underwent a 6-week titration phase, followed by a 12-week maintenance phase; no dose adjustments were allowed.
Of those randomized, 234 completed the trial, 63.2% of the original group. The most withdrawals were in the 600-mg dose group, where only 45.2% of patients completed the trial.