A randomised controlled trial involving nearly 500 people with multiple sclerosis (MS) from across the UK has shown that cannabis derivatives do not slow the progress of the disease as had been hoped. These results were presented at the Association of British Neurologists' conference by Professor John Zajicek of the Peninsula Medical School, Plymouth University.
The CUPID (Cannabinoid Use in Progressive Inflammatory brain Disease) study is the first large non-commercial study to investigate whether the main active constituent of cannabis (tetrahydrocannabinol, THC) is effective in slowing the course of progressive MS.
People with progressive MS remained on treatment with either THC capsules or placebo capsules for three years, and were carefully followed to see how their MS changed over this period. Overall the study found no evidence to support an effect of THC on MS progression when measured by neurologists or patients. It may still alleviate symptoms but there is currently no treatment to prevent MS from progressing.
Andrew Nunn, who was an investigator on the trial, said "It is very disappointing that THC does not seem to slow MS progression. However, one of the other aims of the CUPID study was to improve the way that clinical trial research is done, by exploring newer methods of measuring MS and using the latest statistical methods to make the most of every piece of information collected. The CUPID study will therefore provide important information to help us conduct further large-scale clinical trials in MS in the future."