British biopharmaceutical firm GW Pharmaceuticals has started a Phase Ib/IIa clinical trial for the treatment of recurrent glioblastoma multiforme (GBM).
Glioma is a type of tumour that starts in the brain or spine and GBM is a particularly aggressive tumour that forms from abnormal growth of glial tissue.
Twenty patients will be enrolled in the multicentre, two part Phase Ib/IIa trial with an open-label phase which will evaluate safety and tolerability of GW cannabinoids in combination with temozolomide, and a double-blind, randomised, placebo-controlled phase with patients randomised to active or placebo, and with a primary outcome measure of six month progression free survival.
The main objective of the trial is to evaluate the tolerability, safety and pharmacodynamics of a mixture of two principal cannabinoids, THC and CBD in a 1:1 allocation ratio, in combination with temozolomide in patients with recurrent GBM.
The trial's secondary endpoints include additional pharmacokinetic and biomarker analyses and additional measurable outcomes of tumour response.
GBM has limited treatment options and an expected survival of little over one year; it is considered a rare disease by the US Food and Drug Administration (FDA) and European Medicines Agency (EMA).
The Phase Ib/IIa clinical trial follows many years of pre-clinical research conducted by GW in the glioma area.
Pre-clinical studies showed that cannabinoids inhibit the viability of glioma cells both in vitro and in vivo via apoptosis or programmed cell death, may also affect angiogenesis, as well as showed tumour growth-inhibiting action and an improvement in the therapeutic efficacy of temozolomide, a standard treatment for glioma.
In addition, the company has shown tumour response to be positively related with tissue levels of cannabinoids.
The company has identified the putative mechanism of action for its cannabinoid product candidate, where autophagy and programmed cell death are stimulated via stimulation of the TRB3 pathway.
GW Pharmaceuticals director of research and development Stephen Wright said: "We believe this clinical programme demonstrates the flexibility and broad application of GW's cannabinoid platform to treat significant, unmet therapeutic needs."
Image: Histopathological image of cerebral glioblastoma. Photo: courtesy of KGH.