“We’ve had a change in the laws,” says Gavin Sathianathan. “But that’s a necessary, not a sufficient, condition towards people getting access to cannabis medicines.”
More and more people are using cannabis as a medicine, both in the UK and abroad; and in the UK the rules have changed to allow doctors to prescribe it in certain circumstances. But there are challenges unique to cannabis that make it harder to research, market and prescribe: the usual model of getting a drug to patients, of clinical trials and regulation, hits hurdles with cannabis that you don’t see elsewhere.
Sathianathan is the CEO of a botanical medicines firm, Alta Flora, which makes cannabis-based drugs, among others. He is one of a new breed of cannabis producer who are trying to make the drug scientifically respectable, to put its medical use on an evidence-based foundation like that of other medicines. At the moment, it is often either seen by large parts of the medical establishment as medically useless, or held up by ageing hippies as a quasi-mystical panacea.
“Cannabis is complex, pharmacologically,” he says. “Traditionally, pharmaceuticals tend to be single molecules with a single target. Cannabis is a treasure chest of medicines”.
That makes it harder to study, says Harry Sumnall, Professor in Substance Use at Liverpool John Moores University. “There are some products that are extracts such as Sativex and Epidiolex.” They are drugs that reduce spasticity in multiple sclerosis patients, and reduce the frequency of epileptic seizures respectively. Sativex is already licensed. Epidiolex is approved by the FDA for the treatment of seizures associated with two rare and severe forms of epilepsy, Lennox-Gastaut syndrome and Dravet syndrome, and recently won a positive recommendation for marketing approval from a European Medicines Agency (EMA) panel. But they are specific chemicals, extracted and purified, and tested like any other drug.
Where it gets complex is with “whole-plant” herbal products: flowers, or largely unrefined extracts such as oils. Many people who use, and derive benefit from, cannabis medicines use it in this form. “The plant contains hundreds of cannabinoids and other chemicals,” says Sumnall. “You see this end result, but what actually produced it? Was it the THC, the CBD, the whole product? Translating it to what your GP will prescribe is very difficult”. And the plants and their derivatives are not of standardised strength. “You can’t say ‘take two tablets a day and you’ll be fine’, because it’s so complex”.
Instead, argue some producers and scientists – David Nutt, the former chairman of the government’s Advisory Council on the Misuse of Drugs, among them – we need to find a new regulatory framework for cannabis products, and new ways of testing them.
Elsewhere in the world, notably Australia and the USA, “we’re seeing a shift in the regulatory landscape to accepting real-world evidence,” says Adam James, the commercial director of Emerald Clinics, another medicinal cannabis firm. As well as randomised controlled trials (RCTs), the gold standard of medical trial, there is an increasing use of “post-market surveillance” – data collected from real-world patients who have been given the drug.
That is possible with cannabis in a way that it wouldn’t be with, say, some new chemotherapy drug for cancer, because regardless of whether it’s effective, cannabis has at least been shown to be relatively safe; there is little to no risk of acute reactions.
The problem is that regulators and professional bodies in the United Kingdom are understandably wary, although a lobby group, the Centre for Medicinal Cannabis, recently issued a report on how to gather and use this sort of evidence in the UK, using the Danish and Australian systems as examples.
Cannabis is usually a recreational drug; some of the people who push cannabis as a medicinal drug overstate its efficacy, claiming that it cures practically everything. “We believe there are significant therapeutic benefits, but we do it a disservice by calling it a wonder drug” says Diane Scott, CEO of the Jamaican Medical Cannabis Collective, another medicinal cannabis firm.
Those therapeutic benefits, she is keen to stress, are real for the millions of patients around the world using cannabis as medicine, but the hard medical evidence gathered via traditional means such as RCTs is, as yet, limited. But, if individuals prefer to use cannabis, instead of, for example, opioid-based medicines for some types of pain management, why shouldn’t they be able to? In fact, research teams at major universities in both Australia and Canada are investigating marijuana’s usefulness as a treatment for opioid addictions. (Government health agencies in both countries, as well as the USA have declared the opioid crisis public health emergencies.)
There is evidence of effectiveness in things like appetite stimulation in cancer patients, in pain relief, nausea reduction, and – as with Sativex and Epidiolex – in the reduction of some symptoms of MS and epilepsy.
In the UK, cannabis was moved last year from “schedule 1”, meaning it was considered to have no medical benefits at all, to “schedule 2”, which meant that doctors could prescribe it in certain circumstances.