Introduction
Sativex has been available in Europe since 2010. It is a combination of tetrahydrocannabinol and cannabidiol at a ratio of 1:1 and has been found to be effective in spasticity resistant to medications in patients with multiple sclerosis. Spasticity is the increased tone seen in the muscles due to abnormalities in the central nervous system such as the white matter lesions seen in multiple sclerosis.
Sativex and medically refractory spasticity in multiple sclerosis
Sativex is a THC:CBD (tetrahydrocannabinol:cannabidiol) preparation taken oromucosally which was approved in European countries for the treatment of medically refractory spasticity in patients with multiple sclerosis. Sativex contains a 1:1 ratio of THC to CBD, where THC interacts with CBD receptors to reduce spasticity while CBD ameliorates the side effects often seen with THC. In one large clinical trial of 1615 patients, 42% showed improvement of spasticity in the first 4 weeks, defined as > or = to 20% reduction in spasticity. The responders were double-blinded and grouped under placebo or THC:CBD, a larger proportion of patients had significant response compared to placebo, > or = to 30% reduction of NRS score for spasticity. 47% had adverse effects including fatigue and dizziness. Reported side effects included psychiatric disturbances, 55 had cognitive (attention problems, cognitive worsening and memory problems) and psychiatric issues (confusion, panic attacks, hallucinations, depression and suicidal ideations). Fatigue, drowsiness, dizziness, gastrointestinal symptoms, mouth discomfort and allergic reactions were other reported side effects. There was no evidence of abuse or addiction in the patients. There were significant side effects deemed unrelated to Sativex including, myocardial infarct, hypertensive crisis (2).
In the original MOVE 2 trial in Italy, in the 322 patients studied, the NRS numerical rating scale decreased by -19.1% from baseline time to 3 months of treatment with Sativex. At visit 3 at 3 months, 24.6% were considered relevant responders to the medication with 30% or more reduction in spasticity. Side effects of >1% included somnolence, dizziness, and fatigue. 41 patients reported side effects 3 were serious side effects of which one was not related (3).
Sativex and studies in Germany, United Kingdom, Switzerland and Spain
Sativex was first approved in Spain and the United Kingdom in 2010 for use in spasticity related to multiple sclerosis. Data were collected to study continued efficacy and safety profiles. 941 patients (761 from the UK, 178 from Germany and 2 from Switzerland) were studied. Data was collected up until January of 2015. A patient registry was set up as per guidelines before new medications are approved. Patients from the UK were 22% of the patients registered in the UK using that medication since 2010. Continuation rates were 1 year for 68% of patients. Among those who stopped it, 30% cited lack of effectiveness and 25% described side effects. Some significant side effects include suicidality in 2% and depression in 6%. There was no evidence of abuse, addiction or misuse. The fatigue was within the known safety margins of the drug. The patients used on average 5.9 +/- 4.9 sprays per day
Sativex and timeline when it is found to be ineffective
In one large study in Italy involving 30 multiple sclerosis centers, the discontinuation profile was studied. Patient data from 30 MS centers were collected from a period of January 2014 to January 2015. 39.5% of patients disconnected treatment with Sativex. Spasticity was studied using the EDSS or expanded disability status scale and the patient NRS numerical rating scale 0-10 for spasticity. Information was collected at baseline (T0), 4 weeks (T1), 3 months (T2) and 6 months (T3).
Spasticity was noted in 1615 patients. 1597 (39.5%) discontinued treatment. Of those, 24.8% did not reach 20% effectiveness using the NRS scale. Reasons of discontinuing include lack of effectiveness 23%, side effects 16.3% and lack of compliance 0.8%, lost to follow-up 0.4%, patient choice 0.3% and unknown reasons 2%. Analysis showed that an increase in the NRS scale by 1 point at baseline time corresponded to a lower rate of discontinuation. While an increase in the NRS scale at timeline 2 or at 4 weeks corresponded with worsening spasticity and a higher non-responder rate. They concluded that Sativex is a good option for spasticity and by 4-6 weeks, patients can be reliably identified as responders or non-responders to avoid the cost burden on the healthcare system (1).
Reference
- Messina, et al, “Sativex in resistant multiple sclerosis spasticity: discontinuation study in a large population of Italian patients (SA.FE. study), Public Library of Science PLoS One, 2017, 12(8) e0180651
- Patti, et al, “Efficacy and safety of cannabinoid oromucosal spray for multiple sclerosis spasticity,” Journal of Neurology, Neurosurgery and Psychiatry, 2016, Sep., 87(9):944-951.
- Trojano, et al, “Effectiveness and tolerability of THC/CBD oromucosal spray for multiple sclerosis spasticity in Italy: first data from a large observational study,” European Neurology, 2015, 74:178-185,https://doi.org/10.1159/000441819
- Fernandez, et al, “THC:CBD in daily practice: available data from UK, Germany and Spain,”European Neurology, 2016, 75 (supp 1);1-3, https://doi.org/10.1159/000444234
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