A lack of evidence is prohibiting patients from accessing medicinal cannabis.
In November 2018, the prescription of cannabis-based products for medicinal use (CBPMs) was legalised in the UK. Patients with certain conditions whose needs cannot be met by licenced therapies should now be able to receive these products from specialist consultants. Yet so far, CBPMs have been almost impossible to access, with a recent press report revealing that hundreds of patients have been forced to turn to expensive private clinics in an attempt to gain access to treatment.
NHS England recently conducted a review to understand the barriers to accessing CBPMs within the NHS, in order to support the generation of new evidence, assist clinical decision-making and facilitate adoption.
What are the barriers to prescribing?
The lack of randomised control trial (RCT) data supporting the effectiveness of CBPMs was found to be the biggest concern to clinicians. In particular, the uncertainty over safety and effectiveness was a major hurdle to prescribing. Given their high cost, it is unlikely that CBPMs will be routinely funded by hospital trusts without improved knowledge and an adequate evidence base demonstrating their clinical- and cost-effectiveness and long-term safety.
Is real world evidence the answer?
New evidence bases will require structured data collection for the patient groups that are most in need. RCTs have traditionally been seen as the gold-standard of evidence generation but as a standalone method are timely to complete and are associated with additional methodological and ethical constraints if used to collect data on children, a key demographic requiring CBPMs. The collection of real world data may offer an additional approach to gaining insight into treatment effectiveness and clinical outcomes. Indeed, it was the clear view of many patients and carers who were interviewed as part of the NHS England review that international observational study data should be given much more consideration in light of the current limited evidence base. NHS England have subsequently recommended the development of a national UK patient registry to collect a uniform dataset across all indications using CBPMs. They have also called for an alternative study design to collect evidence for children and young adults currently in receipt of a CBPM, to which an observational study design could be the answer.
Patient voice is key
The real value of CBPMs will likely lie in the potentially life changing effects they could have on the lives of some patients. Currently, those seen as most likely to benefit from treatment are patients with severe treatment-resistant paediatric epilepsy who have typically tried most other licensed medicines, often with little obvious benefit and an increased risk of adverse effects. Real world evidence incorporating the patient perspective via the measurement of patient reported outcomes could provide powerful insight as to the real value of CBPMs in terms of their wider impact on quality of life, symptoms and functioning.
When demand outweighs supply
Until there is a consistent supply of CBPMs, evidence generation and access will continue to be a challenge. Most CBPMs are manufactured outside the UK, so the NHS is reliant on imports, often leading to delays. This has led to some patients travelling abroad to source their medicines and illegally transporting them back to the UK. There is also concern over the quality and consistency of products. Further support will be needed to help minimise disruption to supply routes and to enable stakeholders to gain timely and efficient access to high quality treatments within the UK.
A lesson for the future
The sudden decision to legalise CBPMs has left clinicians and patients in an uncertain position. Robust evidence on the safety and outcomes of CBPMs will help to build confidence on both sides and may increase access by demonstrating cost-effectiveness and paving the way for clearer funding routes. CBPMs are not perceived as a ‘miracle cure’ by any means but may offer a better quality of life for some patients and their families. Equipping patients and healthcare professionals with the guidance and information they need to make informed treatment decisions may help break down existing barriers to accessing CBPMs within the NHS.