Cannabis-based drugs could be prescribed in the United Kingdom as early as 2003 following word from a British pharmaceutical company that four Phase III clinical trials showed the drugs successfully treated symptoms associated with multiple sclerosis and neuropathic pain. In the trials, the pot-based medicine achieved statistically significant reductions in neuropathic (nerve-damage) pain, as well as statistically significant improvements in other symptoms of MS, most notably spasticity and sleep disturbance.From the GW Pharmaceuticals:GW Announces Positive Results From Each of Four Phase Three Clinical Trials
GW Pharmaceuticals plc, the company developing a portfolio of non-smoked cannabis-based prescription medicines, announces positive preliminary results from each of four completed Phase III clinical trials in patients suffering from Multiple Sclerosis and neuropathic pain. As a result of these positive results, GW now intends to submit its first regulatory application to the Medicines Control Agency early next year. Subject to regulatory approval, the UK market launch of GW’s first cannabis-based medicine could be achieved during 2003.
GW’s four randomised, double-blind Phase III trials included approximately 350 patients and are part of the largest clinical programme ever undertaken into the medicinal effects of cannabis. The trials examined, in comparison to placebo, the effectiveness of GW’s whole plant medicinal cannabis extract containing tetrahydrocannabinol (THC) and cannabidiol (CBD) as its principal components. The THC:CBD medicine was administered by means of a spray into the mouth.
In the trials, the THC:CBD medicine achieved statistically significant reductions in neuropathic (nerve-damage) pain, as well as statistically significant improvements in other symptoms of Multiple Sclerosis (“MS”), most notably spasticity and sleep disturbance. These findings are consistent with results from Phase II trials previously announced by the Company.
The four trials examined the efficacy of the THC:CBD product in relieving symptoms in the following conditions:
Neuropathic pain in MS
Pain and sleep disturbance in MS and other neurological conditions
Multi-symptoms in MS
Neuropathic pain in Brachial Plexus Injury
The main summary findings from each of the studies, the full results of which will be submitted for peer-review publication in due course, are provided below. Results quoted as ‘statistically significant’ had an associated probability value (p-value) of less than 0.05, whilst those that are ‘highly statistically significant’ had a p-value less than 0.01.
In a double-blind parallel group study comparing the efficacy of GW’s THC:CBD product with placebo in the treatment of neuropathic pain in 66 patients with MS, the THC:CBD medicine provided highly statistically significant relief of pain in comparison with placebo and highly statistically significant reduction in sleep disturbance.
In a double-blind parallel group study comparing the efficacy of GW’s THC:CBD product with placebo in the treatment of chronic refractory pain in 70 patients with MS and other neurological conditions, the THC:CBD medicine provided statistically significant pain relief (as evidenced by the diminished use of analgesic rescue medication) and statistically significant reduction in sleep disturbance.
In a double-blind parallel group study comparing the efficacy of GW’s THC:CBD product with placebo in the treatment of a number of symptoms in 160 patients with MS, the THC:CBD medicine provided a highly statistically significant improvement in the symptom of spasticity. Positive trends were also observed in a number of other MS symptoms (providing useful additional support to significant results obtained in Phase II trials).
In a double-blind crossover study comparing the efficacy of GW’s THC:CBD product, GW’s THC alone product and placebo in the treatment of neuropathic pain in 48 patients with Brachial Plexus Injury, both the THC:CBD medicine and the THC medicine provided highly statistically significant relief of pain and statistically significant reduction in sleep disturbance. Brachial plexus injury is a rare but particularly challenging cause of intractable neuropathic pain, and to the best of our knowledge this is the first placebo-controlled trial ever conducted in this condition.
The benefits seen in all four studies are all the more notable in that they represent improvements over and above that which patients obtain with their standard prescription medicines (patients receiving both active and placebo medicines continued to take their standard prescription medicines during the trial).
In addition, the trials have demonstrated that GW’s cannabis-based medicine has an excellent safety profile. Self-titration (adjustment) of their dose enabled most patients to achieve improvement in their symptoms without incurring a level of unwanted effects which would interfere with day-to-day living.
Commenting on the trial results, Dr Philip Robson, Medical Director of GW, said “These rigorous randomised placebo-controlled trials indicate that GW’s cannabis-based medicine can provide additional benefits over and above that of standard treatments in these serious and refractory neurological conditions. The results show statistically significant reductions in neuropathic pain, which is recognised as being difficult to treat and is often particularly distressing. There were also significant improvements in other symptoms in patients with MS, notably spasticity and sleep disturbance. In my opinion, it is this broad spectrum of activity, coupled with an excellent safety profile, which gives GW’s cannabis-based medicine the potential to make a unique contribution towards improving the quality of life of patients with these chronic disabling diseases.”
In addition to the four completed trials, GW has a further five Phase III trials in progress. These further studies are examining other potential areas of medical benefit for cannabis-based medicines, including pain in cancer and spinal cord injury, and are expected to complete during 2003. Including these further five studies, GW’s clinical programme will have included over 1000 subjects.
GW’s first regulatory submission will provide evidence of efficacy generated from the positive results from the four completed Phase III clinical trials as well as positive results previously reported from a number of Phase II trials. Safety data will include approximately 350 accumulated patient-years of exposure to the medicine.
Over the past several years, the UK Government has consistently stated that, should a prescription cannabis-based medicine be developed which meets the rigorous standards applied by the Medicines Control Agency, it will amend the legislation so that such a medicine is available for patients.