Top-line results from a phase 2 study suggest vixotrigine (BIIB074, Biogen), a nonopioid investigational oral pain medication, reduces chronic neuropathic pain caused by small fiber neuropathy (SFN) and is generally well tolerated.
“We are encouraged by the overall results of the CONVEY study, especially given the significant unmet medical need for additional agents to treat chronic painful neuropathy,” Katherine Dawson, MD, senior vice president and head of the therapeutics development unit at Biogen, said in a news release.
Vixotrigine (BIIB074) is a peripherally and centrally acting, orally administered, voltage- and use-dependent voltage-gated sodium channel blocker.
CONVEY was a phase 2, placebo-controlled, double-blind, randomized withdrawal study of 265 patients experiencing pain from confirmed idiopathic or diabetes-associated SFN.
Following a 4-week open-label run-in period, 123 responders to vixotrigine were randomly allocated to 200 mg or 350 mg vixotrigine or placebo twice daily for 12 weeks in the double-blind portion of the study.
At week 12, vixotrigine 200 mg twice daily met the primary endpoint of a statistically significant reduction from baseline in the mean average daily pain (ADP) score versus placebo (P = .0501).
A subgroup analysis showed a treatment effect in patients with diabetes-associated SFN but not in the smaller subgroup of patients with idiopathic SFN.
The 200-mg dose also led to a significant improvement over placebo in mean worst daily pain score at 12 weeks (P = .0455).
A numeric advantage of 200 mg vixotrigine over placebo was observed in additional secondary endpoints, including the proportion of patients with at least a 2-point improvement in ADP score and the proportion with at least a 30% reduction in ADP at week 12, but these failed to reach statistical significance.
Vixotrigine 350 mg twice daily did not meet the primary endpoint of mean change in ADP at 12 weeks.
However, treatment at the higher dose led to a significant increase in the proportion of patients who reported being “very much improved” or “much improved” over baseline (P = .0580), Biogen reported.
In addition, a numeric advantage of 350 mg over placebo was observed in the proportion of patients with a 2-point or greater improvement in ADP score and the proportion with at least a 30% reduction in ADP at 12 weeks, but these also did not reach statistical significance.
Both doses of vixotrigine were “generally well tolerated and the safety profile was consistent with previous studies of vixotrigine with no evidence of abuse potential,” the company said.
In the open-label period, common adverse events seen in at least 2.5% of patients were dizziness, headache, vertigo, and nausea; adverse events led 5.3% of patients to discontinue the open-label portion of the study. Across the entire study, most adverse events were mild or moderate in severity.
“The totality of data from the vixotrigine program will inform potential doses for study in future phase 3 clinical trials,” the company said.
A version of this article first appeared on Medscape.com.