GW Pharma is strengthening its focus on oncology after promising mid-stage data for its cannabis-based therapy in patients with a rare and aggressive brain tumour called glioblastoma multiforme (GBM).

The firm unveiled data from a Phase II study testing a proprietary combination of tetrahydrocannabinol (THC) and cannabidiol (CBD) in 21 patients with GBM, which showed a one-year survival rate of 83 percent compared with 53 percent of the placebo arm.

Median survival for the THC:CBD group was greater than 550 days versus 369 days in the placebo group, the London, UK-based biopharma said, also noting that the combination was generally well tolerated with treatment emergent adverse events leading to discontinuation in two patients in each group.

The most common adverse events (three patients or more and greater than placebo) were vomiting (75 percent), dizziness (67 percent), nausea (58 percent), headache (33 percent), and constipation (33 percent).

The findings "suggest that the addition of a combination of THC and CBD to patients on dose-intensive temozolomide produced relevant improvements in survival compared with placebo and this is a good signal of potential efficacy," said Professor Susan Short, PhD, Professor of Clinical Oncology and Neuro-Oncology at Leeds Institute of Cancer and Pathology at St James's University Hospital and principal investigator of the study.

"These promising results are of particular interest as the pharmacology of the THC:CBD product appears to be distinct from existing oncology medications and may offer a unique and possibly synergistic option for future glioma treatment."

GW's chief executive Justin Gover said the results "further reinforce the potential role of cannabinoids in the field of oncology and provide GW with the prospect of a new and distinct cannabinoid product candidate in the treatment of glioma".

"These data are a catalyst for the acceleration of GW's oncology research interests and over the coming months, we expect to consult with external experts and regulatory agencies on a pivotal clinical development program for THC:CBD in GBM and to expand our research interests in other forms of cancer."

GW is currently gearing up to file its cannabis-based drug Epidiolex to treat children with severe epilepsy, following a stream of Phase III trial successes in difficult to treat forms.

"With three positive Phase III trials delivered in 2016, we remain confident in the prospects for Epidiolex's approval and are accelerating our preparations for a highly successful launch," Gover said.

The company reported a fourth-quarter loss of £15.6 million compared to £17.7 million for the year-ago period, but revenues were also down at £2.1 million versus £3.7 million. Cash and cash equivalents on the books at December 31 were £360.2 million.