Is There a Doctor in the House?
Clinicians must take center stage in the future of medical cannabis research
Simon Erridge, Mikael H Sodergren | | Opinion
The cannabis plant has been noted for its medicinal properties for approximately 8,000 years and was first reported in a modern medical journal by WH O’Shaughnessy in an 1840 paper for the Boston Medical and Surgical Journal that described the use of hemp resin in convulsive disorders. Medical use of cannabis continued well into the 1900s before socio-political changes led to its prohibition. Recent changes to attitudes and laws surrounding the use of cannabis has since brought the medicinal potential of the plant back to the attention of patients, doctors, researchers and policymakers. There is huge demand from patients and their families, particularly those who have received significant benefit from cannabis administered off-prescription, to widen access to medical cannabis for a range of ailments.
However, it is difficult for clinicians to prescribe medical cannabis with confidence. Research into the therapeutic properties of the plant has been restricted by its reputation and scheduling as a drug of misuse and we are yet to fully understand how cannabis can be best used in the clinic.
Since Raphael Mechoulam isolated THC – the main psychoactive component of cannabis – in 1964, over 100 cannabinoids have been identified from the cannabis plant. This is in addition to the hundreds of terpenes, flavonoids, stilbenoids, amino acids, fatty acids, alkaloids, hydrocarbons, carbohydrates, and phenols present within unprocessed flower products, many of which have their own touted medical properties. This diversity presents a number of therapeutic opportunities, but has made it difficult to conduct the randomized controlled trials upon which clinicians are accustomed to forming their evidence base.
The Cannabis genus is composed of two well-recognized species (Cannabis sativa and Cannabis indica) and their hybrids. Different cultivars of each species have been developed by growers aiming to adapt the chemical composition and attain specific end-user effects. This presents yet more challenges to interpreting the results of medical cannabis studies. Although inferences can be made according to chemical profile, the results of clinical studies with unprocessed flower or whole plant extract cannot be precisely extrapolated to other products. Until recently, clinical research has also been limited by the lack of adherence to good manufacturing practice, making it difficult to standardize the chemical and therapeutic properties even within the same study. If you are unable to provide standardized medication concentrations, your results are unlikely to supply convincing evidence of benefits or harms.
The challenges of conducting research with unprocessed flower and/or whole plant extracts have encouraged many researchers to focus on cannabinoid isolates, most commonly THC and CBD. This has given us a clearer understanding of the impact of individual compounds in conditions such as treatment-resistant childhood epilepsy syndromes and chemotherapy-induced nausea and vomiting. However, the use of isolated cannabinoids does not necessarily represent the full therapeutic potential of the plant and certainly does not reflect common prescribing practices in mature markets, such as Germany and Canada, where 43 and 41 percent of medical cannabis prescriptions, respectively, are for unprocessed flower.
With so many complicating factors to consider, how can we conduct high-quality clinical trials of medical cannabis products? First, individuals and regulatory bodies must recognize that medical cannabis is not one medicine. Both academics and prescribing clinicians should be involved in the development of trials. Experienced medical cannabis prescribers can help identify specific cultivars for further examination within traditional frameworks set out by experienced clinical trialists. Though many in the cannabis industry refute the calls for randomized controlled data, preferring observational studies, it is important to recognize that performing randomized controlled trials in medical cannabis is in no way impossible, just more challenging. To this end, Sapphire Medical Clinics has developed a clinical trials hub to broaden patients’ access to appropriate studies – both to further our knowledge and to improve access to medications that may not be available to patients outside the context of a clinical trial.
Sapphire Medical Clinics is well placed to recruit trial participants, having been set up to provide a second opinion service to doctors to assess whether a patient may benefit from a trial of cannabis-based medicine. Our doctors are guided by clinical evidence through a rigorous clinical governance framework and provide thorough post-treatment monitoring.
Though they provide the highest level of evidence in investigating medical cannabis, clinical trials are often expensive and time-consuming. While we wait for this data, it is important that regulators look to other methodologies to investigate the effects of medical cannabis. One way to do this is to collect large-scale observational data. This is the premise behind the formation of the UK Medical Cannabis Registry. Established by a group at Sapphire Medical Clinics, the registry seeks to capture essential data, including prescribed formulations, adverse events, and patient-reported outcome measures across a range of conditions. Open to both NHS and private prescribers, the registry will be important in providing data to national regulators to help inform their guidelines in the future. Clinicians have been an integral part of these efforts; for example, helping to identify clinically important outcome measures to study chronic diseases.
Traditional pharmaceuticals run through pre-defined stages of in vivo studies, clinical trials and post-marketing research. In medical cannabis, all three are now running concurrently. As such, physicians will play an important role in dictating the future direction of medical cannabis research.