Influence of Previous Failed Antispasticity Therapy on the Efficacy and Tolerability of THC:CBD Oromucosal Spray for Multiple Sclerosis Spasticity

Abstract

Background: Sativex® (THC:CBD oromucosal spray) is indicated as add-on treatment for patients with moderate to severe multiple sclerosis (MS) spasticity. We aimed to determine whether antispasticity treatment history influenced the efficacy and safety of add-on THC:CBD oromucosal spray in MS spasticity patients. Methods: Post hoc analysis of an enriched-design clinical trial of THC:CBD oromucosal spray versus placebo, using records of patients under previous and current ineffective antispasticity therapies. Subgroups were patients with at least 1 failed therapy attempt with either baclofen or tizanidine (Group 1) or at least 2 failed therapy attempts with both baclofen and tizanidine (Group 2). Summary: Of 241 patients in the intent-to-treat population, 162 and 57 patients met the criteria for Groups 1 and 2, respectively. In all groups, response on the spasticity 0-10 Numerical Rating Scale was significantly greater with THC:CBD oromucosal spray versus placebo, for minimal clinically important difference (MCID ≥18% improvement vs. baseline) and clinically important difference (CID, ≥30% improvement vs. baseline). THC:CBD oromucosal spray improved spasticity-related symptoms such as sleep quality and timed 10-meter walk independent of the number of prior failed therapy attempts. Tolerability was not influenced by pre-treatment history. Conclusions: THC:CBD oromucosal spray provided consistent relief with good tolerability in MS spasticity patients irrespective of their antispasticity pre-treatment history.