Cost effectiveness of oromucosal cannabis-based medicine (Sativex®) for spasticity in multiple sclerosis.
Spasticity is common in patients with multiple sclerosis (MS) and is a major contributor to disability. Sativex®, an oromucosal spray containing cannabis-based medicinal products, has been found to be effective in reducing spasticity symptoms. Our objective was to estimate the cost effectiveness of Sativex® plus oral anti-spasticity medicines compared with the current standard treatment for moderate or severe spasticity in MS in the UK. A Markov model was used to assess the costs and benefits of Sativex® plus oral anti-spasticity medicines or current standard treatment based on their effects on the quality of life of patients. The main outcome was the incremental cost-effectiveness ratio (ICER) in terms of costs per additional QALY gained over 5 years of treatment. One-way, multi-way and probabilistic sensitivity analyses were conducted to explore the impact of uncertainties on the findings. In the base case, Sativex® plus oral anti-spasticity medicines resulted in incremental costs of £7600 and a QALY gain of 0.15 per person over 5 years (ICER £49 300 per QALY).year 2009 data for costs. Findings were sensitive to the costs of Sativex® (price and dose) and differences in utilities between responders and non-responders. Using a willingness-to-pay threshold of £30 000 per QALY, Sativex® appears unlikely to be considered cost effective by UK funders of healthcare for spasticity in MS. This is unfortunate, since it appears that Sativex® use is likely to benefit some patients in the management of this common consequence of MS.