First legal medicinal cannabis product in Ireland lacks evidence base, specialist warns

Prof Bryan Lynch says ‘no evidence’ of benefits to epilepsy patients from THC products

The first legal medicinal cannabis product will be available to eligible patients from next month. File photograph: Mauro Pimentel/AFP via Getty Images
The first legal medicinal cannabis product will be available to eligible patients from next month. File photograph: Mauro Pimentel/AFP via Getty Images

The first legal medicinal cannabis product will be available to eligible patients from next month, but a specialist consultant has said he would not prescribe it due to the absence of a scientific evidence base for its efficacy.

CannEpil, a cannabis-based oral solution intended for drug-resistant epilepsy, is due to be accessible from mid-October as part of the Health Service Executive’s (HSE) Medicinal Cannabis Access Programme (MCAP). It has a high level of cannabidiol (CBD) and a low level of tetrahydrocannabinol (THC), the psychoactive component of cannabis, at a ratio between the two of 20:1.

Under the 1977 Misuse of Drugs Act any substance containing even trace levels of THC is a controlled drug. Only a medical consultant will be able to prescribe a cannabis-based product to a registered patient, who must have already exhausted all other treatment options, the Oireachtas health committee heard on Wednesday. As well as patients with severe and treatment-resistant epilepsy, the MCAP scheme is designed for people with spasticity associated with multiple sclerosis and chemotherapy patients suffering intractable nausea and vomiting.

However, consultant paediatric neurologist at Children’s University Hospital Temple Street Prof Bryan Lynch told the committee that there is “no evidence base” for benefits to epileptic patients from cannabis products that contain a THC component.

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“For us clinicians looking after patients with epilepsy the evidence base is for pure CBD products,” he told the committee.

Clinicians want a “reliable, properly formulated” product to prescribe to patients “as soon as possible”, he added. The upcoming MCAP products do not meet this standard for epilepsy patients, he said, but the market approval of a newly licensed CBD-based medicine, Epidiolex, would solve this problem.

“I can speak for my colleagues [to say] that we would not be prescribing CannEpil because that has a significant THC component and there is no evidence base for such a product to be effective for children and adults with epilepsy,” he said.

‘Strange situation’

People Before Profit TD Gino Kenny, who spearheaded a campaign to legalise medicinal cannabis, said it is “strange” that doctors do not want to prescribe the first MCAP product, which comes after a “protracted” campaign and approval process. Prof Lynch agreed it is a “strange situation”, but he said he has no control over what will be approved through the MCAP scheme.

Shaun Flanagan, the assistant national director of the HSE's Primary Care Eligibility and Reimbursement Service (PCERS), told the committee that CannEpil will be the only cannabis-based product to come on stream this year, while another oral solution, Tilray, has agreed a price with the HSE and has signalled its intention to enter the Irish market. Two other producers given the go ahead do not currently have plans to sell here, despite going through the approval process, Mr Flanagan said.

In response to a question from Sinn Féin health spokesman David Cullinane on the likely success of the scheme, Mr Flanagan said he has "no idea" how much demand there will be for the scheme. Mr Flanagan said the licensing of Epidiolex has "changed the picture" since the programme was first conceptualised. An estimated 300 to 600 epilepsy patients who might have applied for MCAP products could be better served with Epidiolex if it receives market approval, he said.

‘Better option’

Lorraine Nolan, chief executive of the Health Products Regulatory Authority (HPRA), said cannabis-based products used for medicinal purposes "should not be confused with authorised medicines", which are a better treatment option if available, she said. There is a "low regulatory burden" overseeing the approval of products for MCAP, while authorised medicines undergo a "comprehensive clinical and quality evaluation", including clinical trials to assess their safety and efficacy, she added.

She noted that scientific data relating to the medical use of cannabis was “extremely limited” when the HPRA conducted its 2017 review of the benefits and risks of cannabis products for medical use. The data, she said, fell “well short of the standard required for medicine to receive market access”. The HPRA will monitor reports of suspected adverse events from MCAP products and review them for any signals of safety concerns, she added.

Ellen O'Riordan

Ellen O'Riordan

Ellen O'Riordan is High Court Reporter with The Irish Times