6 April 2000
GW Pharmaceuticals to proceed with patient studies of Medicinal Cannabis
The first clinical trials of cannabis-based medicines involving patients suffering from MS, spinal cord injury and other forms of severe pain and spasticity have been given permission to proceed by the UK medical authorities. GW Pharmaceuticals, the company licensed by the UK Home Office to undertake a pharmaceutical research and development programme to develop prescription cannabis-based medicines, will commence these Phase 2 trials in the near future.
Dr Geoffrey Guy, Chairman of GW Pharmaceuticals, said, "Entering Phase 2 trials is a highly significant point in the development of cannabis-based medicines. These trials will allow us to demonstrate efficacy in a limited number of subjects and to establish the necessary dosage regimen and delivery mechanisms to provide the most effective relief to sufferers from the acute pain and spasticity associated with MS and other neurological disorders."
GW has been granted a clinical trial exemption certificate (CTX) by the Medicines Control Agency (MCA). The CTX is a requirement for any pharmaceutical company wishing to carry out patient studies in the UK.
The trials, to be conducted at a number of locations, will commence in the Pain Relief Clinic at the James Paget Hospital, Great Yarmouth, under the supervision of Dr Willy Notcutt.
Dr Notcutt said, "Our aim is to test some of the claims which have been made for the medicinal qualities of cannabis in a structured clinical research programme. This is an exciting moment, and we hope very much that our findings will lead to significant improvements in the pain relief available for sufferers of MS and other debilitating conditions."
Patients will take different formulations of cannabis-based medicines by means of a sub-lingual spray device - it is sprayed under the tongue and absorbed, rather than swallowed. Initially, a limited number of patients will take part; but as data is collected and analysed the trials will be extended. It is anticipated that over the next two to three years some 2000 patients will be involved in the trials programme. Doctors or patients interested in the trials can find out more at www.medicinal-cannabis.org.
The aim of GW's clinical development programme is to prepare data for Product Licence Approval. In the event of a Licence being granted, the UK Government has indicated that it would be willing to amend the Misuse of Drugs Act 1971 to allow the prescribing of a cannabis-based medicine. GW hopes to bring to market prescription medicines as early as 2003. This will allow sufferers of MS and other conditions to experience the medical benefits of cannabis without unwanted psychoactive side effects, and without the health dangers associated with smoking.
Dr Guy added, "There is a considerable body of evidence to suggest that cannabis may have a number of medicinal uses, including the relief of pain and spasm in multiple sclerosis, and for pain relief in disorders such as spinal cord injury and neuralgia. We are now well on the way to being able to demonstrate this in a controlled clinical research environment."
Notes to Editors
GW Pharmaceuticals Ltd is a private limited company, set up in December 1997 after discussions with UK government officials. The company operates licences issued by the UK Home Office to cultivate, possess and supply cannabis for medical research purposes.
Clinical research programme: GW's clinical research programme is being carried out by a team of pharmaceutical professionals experienced in drug development and, in particular, the development of plant-based medicines and drug delivery systems. GW's team is also supported by a number of prominent scientific advisers in this field in Europe and North America. GW has developed sub-lingual sprays that enable the material to be absorbed directly into the blood stream via the mucosa under the tongue, rather than swallowed. The sprays contain formulations of pharmaceutical grade extracts of specific varieties of the cannabis plant. These varieties are selected for their content of two principal cannabinoids, THC and CBD.
GW's Phase 2 trials will begin in small groups of patients. Test medicines will comprise cannabis-based medicinal extracts consisting of different cannabinoid ratios and placebo. The trials will be "double blind", that is, neither patient nor doctor will know which material is being tested on each occasion. Specific aspects of the patients' condition will be studied to demonstrate the effects of the drug and to establish a dose/response relationship. Having established an acceptable dose range and having shown therapeutic benefit in Phase 2, large-scale studies will be undertaken in Phase 3. Hundreds of patients may be entered into each study, which may compare active formulations with a placebo in a random order. Overall, the programme may involve some 2000 patients in the UK.
A number of clinical trial protocols have already gained Ethics Committee approval. Some of these studies will utilise the "n of 1" principle in which each patient is the complete study acting as his or her own control. This study design can be adapted to a wide variety of therapeutic indications and research environments.
In a Phase 1 study which was completed during November 1999, a small group of subjects took formulations of cannabis consisting of different ratios of cannabinoids. Mature subjects were recruited for GW's study by a specialist clinical trials unit. They took the drug sub-lingually and also by means of an inhaler. The study entailed measuring blood levels and conducting physiological and cognitive testing throughout. The tolerability, blood level and cognitive data obtained enabled GW to establish the safe envelope of usage.
GW has set up a database for patients who may be suitable for participation in clinical trials. The database, now numbering over 1000 patients, will prove immensely valuable in the selection of participants for the later clinical trials but will also provide data likely to play a central role in the design and scale of the subsequent long term safety study or other trials. This information is also giving invaluable insight into the nature and extent to which cannabis is already taken as medicine across the UK.
Cultivation programme: GW has more than 10 years research expertise on cultivation and analysis of the cannabis sativa plant; the GW laboratory is undertaking a ground-breaking programme of formulation work for clinical delivery. The strategy of GW is to ensure quality and consistency at the starting material stage by using defined clones from specific varieties of the plant, and by implementing strict control of the growing conditions. GWÂ¹s plants are grown in a highly secure glasshouse facility. All aspects of the growing climate - temperature, humidity, air changes and photoperiod - are controlled by computer. Strict Standard Operating Procedures are observed to ensure non-contamination by chemicals, infestation or fungal growth, consistency of content, methods of harvest, drying, primary extraction, storage, and onward consignment.
Dr Geoffrey W Guy, Chairman of GW Pharmaceuticals, is a pharmaceutical physician with 18 years experience in pharmaceutical development covering New Chemical Entities, Biotechnology products, plant based medicines and drug delivery systems. Dr Guy has been the physician in charge of over 250 clinical studies including first dose in man, pharmacokinetics, pharmacodynamics, dose ranging, controlled clinical trials, and large scale multi-centered studies and clinical surveys. Specialist areas of interest include Narcotic Analgesics, Hormone Replacement Therapy, Asthma and Eczema. Dr Guy was the founder of Ethical Holdings plc, the pharmaceutical drug delivery group, and of Phytopharm plc, a phytomedicines company.
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