The Medical Research Council (MRC) approved a grant of almost pounds 1m yesterday for a three-year study of the drug which people with MS say can ease symptoms. The drug will be given orally because a pill is thought to be more acceptable for patients. But critics believe it will be too slow to take effect and will increase the risk of side-effects.
The trial, to be run in conjunction with the Multiple Sclerosis Society, will involve 660 patients who will be given one of three treatments. These will contain cannabis extract, the active constituent tetrahydrocannabinol or a placebo containing vegetable oil.
A second trial by the company GW Pharmaceuticals will involve 2,000 patients suffering from MS, spinal cord injuries and intractable pain, who will be given the drug as drops under the tongue, a spray or an aerosol to be inhaled. The company has a licence to grow the drug and has 20,000 plants from which to produce pure extracts.
Dr John Zajicek, consultant neurologist at Derriford Hospital in Plymouth, who will lead the MRC trial, said: "We hope the study will provide definitive scientific evidence about whether or not taking cannabis is helpful to people with MS."
Dr Geoffrey Guy, director of GW Pharmaceuticals, said it was more difficult for patients to judge the right dose using oral preparations of the drug because it took 90 minutes to reach its peak level in the blood.
The dose could be either too little to control the symptoms or too much, causing side- effects. With drops under the tongue the effects were felt in minutes and the dose was easier to adjust. "I think we might get clearer, cleaner results using a non-oral route," he said.
Both research groups welcomed yesterday's announcement by the MRC as indicating growing acceptance of the potential of cannabis as a medicinal treatment.
Peter Cardy, chief executive of the Multiple Sclerosis Society, said: "The trial will provide us with the evidence we need to know whether cannabis or cannaboids [extracts of the drug] are a safe and effective treatment of spasticity in MS."
Clare Hodges, who heads the Alliance for Cannabis Therapeutics, said she was forced to break the law to relieve the symptoms of MS. "I tend to smoke it because it gives an instant hit, which is what you need with MS. If I wake up at night with spasms or feeling really sick and ill, I can have a smoke and feel better."Reuse content