Cannabinoid patenting – a rolling stone?
11 September 2019
The art, the science and the haze
Out of the scores of cannabinoids found in marijuana and hemp plants, cannabidiol (CBD) and tetrahydrocannabinol (THC) are the two primary compounds of interest. CBD is often said to lack the psychotropic effects of THC. Accordingly, CBD on its own, in “pure form”, is not considered a controlled substance under the Misuse of Drugs Regulations. However, it is said that CBD is very hard to purify and given that many products’ packaging either does not fully explain their contents, or are not supported by sufficient chemical analysis, the UK Home Office will presume such products contain other cannabinoids. It is still possible, however, for such CBD-containing products with incidental other cannabinoids, to be in the medically allowed schedule of the controlled substances legislation. To complicate matters further, there are different types of THC, some considered controlled, and others not. Moreover, it is also possible that some non-controlled substances can degrade into controlled ones.
In addition to navigating criminal legislation, there remains a fairly wide perception in the medical community that there is not yet enough evidence of the benefits versus long term potential dis-benefits of many non-medically approved cannabinoid products. Those that want to try cannabis-derived products are free to do so (as with other less regulated substances and supplements such as vitamins, minerals, oils and herbal extracts), and a plethora of such products can be found as supplements ostensibly with health benefits, as well as in products such as cosmetics and foods. In terms of medically approved products, Sativex®, a treatment for spasticity in multiple sclerosis containing both CBD and THC, appears to be the only medicines regulator-approved product in the UK; although an approval for Epidiolex®, a CBD-based product also belonging to GW Pharma, is pending with the European Medicines Agency and has already received FDA approval for treating seizures in two rare types of epilepsy.
What’s being patented?
Some of the popular media suggests that because the cannabis plant has been used for thousands of years, cannabinoid products cannot be patented. Of course, this is not necessarily true. In addition, there is reportedly not much prior art available in this field given that such activity would have been illegal. However, given the acceleration in the number of non-medically approved cannabinoid products, the market may now become awash with prior uses which might be used in invalidity attacks against patents for such products.
Isolation / extraction and delivery methods
While there are plenty of products available on the market with varying claims as to their contents, it is hard to verify these contents, and to ensure consistent batch production and stability. As already mentioned, it is understood that purification of CBD is a non-trivial hurdle. The same is true with THC according to the UK Home Office; in particular because, whilst pure THC-A could be used and is not stable and readily degrades into THC, which is a controlled substance. Accordingly, processes to isolate, extract and purify cannabinoids, may well be patentable, as well as any stable forms themselves.
Multiple types of delivery system already exist, including: transdermal, nebulisation and formulations for vaping, as well as, of course, the more traditional mode of smoking the substances and inhaling them that way. Adaptation of these devices for use with cannabinoid products may well be novel, but may not involve a sufficient inventive step.
The Health and Social Care Committee in the UK has recently published a report about medical cannabis3, in which it, and many organisations giving evidence to the Committee, call for more clinical trials to substantiate some of the health claims of cannabinoids. However, constructing clinical trials to the normal double-blind standards can be difficult with human subjects, particularly with products containing THC, as patients know they are not receiving placebo, because they experience the “high” produced by the THC.
In addition to being a regulatory issue, difficulties in carrying out clinical trials are also potentially a patent issue insofar as it is necessary for a patent to enable the skilled person to use the invention across the breadth of the patented claims. Such disclosures in the patent are not only an issue in relation to ‘sufficiency’, but also an inventive step.
The issue of ‘public morality’ is a rarely used objection to patents in the UK and the EPO. Indeed, even if the invention’s commercial exploitation is illegal, this does not necessarily mean a patent for it is prohibited under the UK Patents Act.
Certainly lack of patentability due to it being against public morality is a high hurdle and while there have not been many English court decisions, in essence the requirement is that the subject of the patent must be something which a large proportion of people would find abhorrent – which is arguably less likely when considering the medical use of cannabis.
Where is all this going?
From a patent standpoint, these are still early days for seeing the shape of the cannabinoid marketplace, given the liberalisation of the substances for medical use only happened around six months ago in the UK and is still evolving in the USA, with liberalization in many US states but still not formally at the federal level. Patent applications can take around 18 months to be published and with the prohibitions in place earlier, a lot of companies will have experienced difficulties obtaining funding and material supplies for carrying out necessary activities to commercialize cannabinoid products. The problem of obtaining clinical proof of benefit for these compounds, can still make it a compliance headache for companies to get involved in this area. But the tide will likely shift to some extent over the next couple of years in line with legal relaxation on these previously banned substances.
This article was first published in The Patent Lawyer Magazine (https://patentlawyermagazine.com/)
 which must comprise cannabis, cannabis resin, cannabinol or a derivative.
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