New analysis shows benefits for patients in 2 clinical trials
by Marisa Wexler, MS |
“In this analysis, nabiximols was shown to significantly [ease] spasticity across a range of outcome measures that reflect various approaches to the evaluation of spasticity in MS patients,” the researchers wrote.
“The clinically meaningful Spasticity NRS [rating scale] results are accompanied by positive findings for change in spasm count in both [the] GWSP0604 and SAVANT [clinical trials] and improvements in spastic muscle tone in SAVANT,” the team wrote, noting that Spasticity NRS “easily assesses the patients’ own daily experience, which is vital, especially for complex constructs such as spasticity.”
The study, “Efficacy of nabiximols oromucosal spray on spasticity in people with multiple sclerosis: Treatment effects on Spasticity Numeric Rating Scale, muscle spasm count, and spastic muscle tone in two randomized clinical trials,” was published in Multiple Sclerosis and Related Disorders. The work was funded by GW Pharmaceuticals, now part of Jazz Pharmaceuticals, the developer of nabiximols.
Nabiximols approved in some countries but not in US
Spasticity, in which muscles become abnormally tight over time, leading to stiffness and in some cases pain, is a common symptom of MS, affecting most people with the disease. Spasticity can be uncomfortable and make it harder to move around, and studies have suggested that MS patients who experience more spasticity tend to report poorer quality of life.
Nabiximols is approved to treat MS-related spasticity in many countries, including Canada and much of Europe, where Jazz markets the therapy under the brand name Sativex. However, the treatment is not approved for use in the U.S.
The oral spray therapy contains delta-9 tetrahydrocannabinol (THC) and cannabidiol (CBD), the two main biologically active compounds found in the cannabis plant. THC is mainly responsible for the high associated with cannabis use, while CBD is thought to have anti-inflammatory and anxiety-relieving effects on the body.
Several clinical trials have tested nabiximols in people with MS-related spasticity. Here, scientists conducted analyses from two such trials: GWSP0604 (NCT00681538), completed in 2009, and SAVANT (NCT00711646), which concluded in 2004. Most participants in both trials were also taking other anti-spasticity medications in addition to nabiximols.
Both of these studies included a run-in period in which all participants were treated with nabiximols. All self-rated their spasticity on a scale from 0 to 10 on the MS Spasticity Numerical Rating Scale (NRS), in which higher numbers reflect worse spasticity. Patients whose scores improved by at least 20% were deemed responders, and were selected to continue into the main phase of the trial, where participants were randomly assigned to receive nabiximols or a placebo.
The identification of responders to test in the main trial “was done to better reflect clinical use, since patients who do not respond to nabiximols are unlikely to remain on treatment, while those that do respond could experience substantial benefits,” the researchers wrote.