Disappointing Phase 2 Results Announced for Cannabis-Based Epilepsy Medication
A proposed cannabidiol medication for epilepsy failed to reduce seizures during a phase 2 clinical trial.
Zynerba Pharmaceuticals, Inc., announced top-line results from its phase 2 STAR 1 (Synthetic Transdermal Cannabidiol for the Treatment of Epilepsy) clinical trial evaluating ZYN002 (cannabidiol [CBD] gel) in adult epilepsy patients with focal seizures. ZYN002 did not demonstrate a statistically significant reduction of focal seizures during the treatment period compared to the baseline period for either the high or low dose cohorts compared to placebo.
“We are very disappointed that the STAR 1 trial did not meet its primary endpoint in this patient population,” said Armando Anido, Chairman and Chief Executive Officer of Zynerba. “We are continuing to evaluate this study and the ongoing STAR 2 open label study to determine next steps with ZYN002 in adult epilepsy patients with focal seizures.”
Anido noted that the results showed “a very favorable safety and tolerability profile” for the product, which is in development for a wide range of indications including osteoarthritis and Fragile X syndrome.
In the double-blind, multicenter STAR 1 trial, 188 patients were randomized to receive195 mg of ZYN002 4.2% CBD gel every 12 hours; 97.5 mg of ZYN002 4.2% CBD gel every 12 hours; or placebo gel every 12 hours for 12 weeks. Patients ages 18 to 71 years of age with confirmed refractory epilepsy with focal seizures with or without secondary generalization were enrolled in this study. Enrolled patients had a median monthly seizure frequency of 10.6, and were on an average of 2.5 antiepileptic drugs (AEDs).
The primary endpoint assessed the median percentage change in seizure frequency over the 12-week treatment period compared to the eight-week baseline period. Secondary endpoints included proportion of patients with at least a 50% reduction from baseline in seizure frequency, percent change from baseline in seizure frequency, change from baseline in seizure frequency, seizure-free days, and 100% seizure free. Safety and tolerability were also evaluated. The study was conducted at 14 sites in Australia and New Zealand. The efficacy analysis included 186 patients.
Patients on the low dose of ZYN002 (n = 63) achieved an 18.4% median reduction in focal seizures during the treatment period compared to baseline; patients on the high dose of ZYN002 (n = 62) achieved a 14.0% median reduction in focal seizures during the treatment period compared to baseline; and patients on placebo (n = 63) achieved an 8.7% median reduction in focal seizures during the treatment period compared to baseline. None of the secondary endpoints showed statistically significant differences between ZYN002 and placebo.
Cannabinoids are a class of chemical compounds found in the Cannabis plant. The two primary cannabinoids contained in Cannabis are cannabidiol, or CBD, and ∆9-tetrahydrocannabinol, or THC. Clinical and preclinical data support the potential for CBD in treating epilepsy, arthritis, and Fragile X Syndrome, and THC has positive effects on treating pain.
ZYN002 is a clear, permeation-enhanced gel that is designed to provide controlled drug delivery transdermally with once- or twice-daily dosing.
Source: Zynerba; August 7, 2017.