UK drugmaker GW Pharmaceuticals has unveiled top-line, mid-stage trial data raising hopes that its cannabis-based drug cannabidiol might prove an effective treatment for schizophrenia.

The exploratory Phase IIa placebo-controlled clinical trial involved 88 patients with schizophrenia who had previously failed to respond adequately to first-line treatment with antipsychotics.

Specific findings were not released at this stage, but GW said that over a range of clinical endpoints cannabidiol (CBD) consistently outperformed placebo, and that the proportion of responders was also higher in the active treatment group.

Crucially, the firm said the safety profile of CBD was “particularly reassuring”, with no serious adverse events and an overall frequency of adverse events very similar to placebo, the most common being diarrhoea (9.3% CBD vs 4.4% placebo), nausea (7% vs 0%), headache (7% vs 8.9%) and somnolence (0% vs 6.7%).

"These findings further reinforce the potential role of cannabinoids in the field of neuropsychiatric disease," said GW’s chief executive Justin Gover. “We believe that the signals of efficacy demonstrated in this trial, together with a notably reassuring safety profile, provide GW with the prospect of new and distinct cannabinoid neuropsychiatric product pipeline opportunity”.

He also noted that, along the same lines as the approach for Epidiolex, which is being developed for forms of childhood epilepsy, the firm’s future research in the area “may lie within paediatric orphan neuropsychiatric indications and we intend to explore this as a focus for future trials”.