Sativex (nabiximols), a THC:CBD oral spray, consistently relieves the pain and severity of treatment-resistant spasticity in multiple sclerosis (MS) patients, according to a recent study.
An analysis of the Sativex as Add-on therapy Vs. further optimized first-line ANTispastics (SAVANT) study revealed that Sativex, used in conjunction with an anti-spasticity medication, provided strong and consistent relief from the symptoms and pain of drug-resistant MS spasticity.
Importantly, Sativex provided nearly the same amount of relief to all surveyed patients, regardless of the degree and duration of their spasticity.
The study reporting the findings, “Tetrahydrocannabinol and cannabidiol oromucosal spray in resistant multiple sclerosis spasticity: consistency of response across subgroups from the SAVANT randomized clinical trial,” was published in the International Journal of Neuroscience.
Spasticity is a common and disabling symptom of MS, and consists of continuous involuntary muscle contractions. The stiffness and tightness of the spastic muscles can interfere with normal movement, speech, and gait. Other symptoms associated with spasticity include pain and sleep disturbances.
Studies suggest that approximately one-third of MS patients experience moderate spasticity within 10 years of their initial diagnosis, and the severity of spasticity directly correlates with one’s well-being and overall quality of life.
Although several anti-spastic medications exist, some MS patients are resistant to them. That’s why there is a medical need to find relief for those patients.
Sativex is an oromucosal spray, developed by GW Pharmaceuticals, containing a cannabis extract of tetrahydrocannabinol and cannabidiol (THC:CBD). It is approved in the EU and other regions as an add-on treatment for adult patients with moderate-to-severe resistant MS spasticity.
An international team of researchers now reviewed data from the SAVANT study, a double-blind, placebo-controlled randomized trial that evaluated the effectiveness of Sativex THC:CBD spray used together with anti-spastic medication in patients with resistant spasticity.
Resistant spasticity was defined in the study as having moderate-to-severe spasticity, for which two standard anti-spasticity therapies (such as baclofen, tizanidine, or dantrolene) had not provided adequate relief.
The SAVANT study did not specifically answer what effect the degree of severity, pain, or duration of an MS patient’s spasticity might have on the amount of relief experienced by Sativex treatment.
To address this, the team measured and compared the changes in spastic severity and pain of specific groups of patients over the course of the study. Groups were defined by disability status, spasticity severity, and spasticity duration.
Disability status groups were set based on disability scores (expanded disability status scale, EDSS scores): those under 6 (ambulatory) versus those with a score of 6 or higher. Spasticity severity was grouped by patients’ Numerical Rating Scale (NRS) score: those scoring 4–6, versus more than 6. Duration of spasticity groups were those experiencing spasticity for less than 5 years versus 5 years or more.
Measuring the reported changes in spasticity and pain severity from baseline to week 12 (the trial’s end), the team found that Sativex halved the mean spasticity and pain severity scores across all patient groups, compared to more modest results in the placebo groups.
“Active [Sativex] treatment significantly improved mean spasticity severity scores versus placebo from week 4 onwards in both EDSS subgroups, in the severe spasticity subgroup, and in both spasticity duration subgroups,” researchers wrote.
In patients with severe spasticity (those with NRS score higher than 6), in particular, Sativex was significantly superior to placebo, leading to a 49% reduction in mean NRS score from baseline. (A lower NRS score represents less severity.)
In turn, patients with moderate spasticity (NRS score of 4 to 6 at randomization) achieved a 51% reduction in the baseline mean NRS score upon treatment with Sativex. However, this difference was not statistically significant compared with placebo. The team believes this might be due to the small size of this subgroup (14 subjects), and to the relatively high placebo effect seen in the moderate spasticity subgroup.
Overall, the team concluded that “add-on THC:CBD oromucosal spray [Sativex] consistently relieves resistant spasticity,” they wrote, noting that “patients with severe resistant spasticity achieve significant therapeutic gains.”
