Jul 23, 2013
Results have been reported from a clinical trial testing whether dronabinol (a synthetic Cannabis/marijuana derivative) slows progression in people with primary-progressive or secondary-progressive MS. This three-year trial, conducted based on previous lab studies suggesting these types of “cannabinoids” may protect the nervous system, was unable to show benefits against progression. Results of the CUPID trial were announced in 2012, and were published early online on July 13, 2013 in Lancet Neurology by Dr. John Zajicek (Plymouth University Peninsula Schools of Medicine and Dentistry) and colleagues in the United Kingdom.
Background: Well known for its mind-altering properties, marijuana is produced from the flowering top of the hemp plant, Cannabis sativa. Various derivatives and synthetic versions of Cannabis, and the plant itself, have been tested for different MS symptoms, with mixed results. The National MS Society is currently supporting a clinical trial of different forms of Cannabis products to test their ability to relieve spasticity in people with MS. This California-based trial is currently recruiting participants.
The CUPID study reported here was based on data from the laboratory suggesting that cannabinoids may offer protection against nervous system damage such as that caused by MS. The CUPID study was funded by the UK Medical Research Council, UK MS Society, MS Trust and others. Dronabinol is a synthetic version of tetrahydrocannabinol, taken orally as a capsule.
The study: Dr. Zajicek and colleagues conducted the multi-center CUPID (cannabinoid use in progressive inflammatory brain disease) trial involving 498 people with primary- or secondary-progressive MS. Participants had varying degrees of gait impairment and other symptoms.
Two-thirds of the participants were administered oral dronabinol, and one-third took inactive placebo, for three years to see if dronabinol could slow progression of MS.
The primary outcomes that were measured after three years were progression in the EDSS (expanded disability status scale) score and change in a portion of the MS Impact Scale related to physical impact (MSIS-29-PHYS; self-reported by the patient). Imaging of the brain using MRI was also performed to look for shrinkage (atrophy) of the brain and to measure MS disease activity. Disease progression was checked at 3 and 6 months and then every 6 months for 3 years.
Results: Although no serious safety concerns were identified, unfortunately, dronabinol was unable to stop MS disease progression or brain atrophy, and did not affect the occurrence of new areas of disease activity in the brain. Analysis of a subgroup of people in this study suggested a possible benefit from dronabinol in those who began the trial with milder disability, but not in those who began the trial with more severe disability. The observation of no effect on brain shrinking suggests that dronabinol does not protect the brain, at least in these circumstances and in this population. Whether dronabinol can protect the brain during earlier stages of MS remains to be tested.
The authors note that participants in both the treatment and placebo arms experienced less disease progression than was expected over the course of the trial. This makes identification of a treatment benefit more difficult to detect.
The EDSS itself has limitations, and the National MS Society is supporting efforts to find better ways to assess disability and to identify biomarkers to more precisely and objectively measure possible therapeutic benefits.
The search for treatments that can stop MS disease activity and progression is an important research priority for the National MS Society, and the Society is currently sponsoring several clinical trials of neuroprotective therapies in people with MS. Download a fact sheet about National MS Society research efforts in progressive MS.
Read more about research in progressive MS.