Objectives Medical cannabinoids have become increasingly popular over the last decade. Preclinical trials suggest cannabinoids, for example, cannabidiol (CBD), may provide an anticancer effect; however, good-quality clinical information supporting this is lacking. We assessed the effect of CBD treatment on disease progression and survival in patients enrolled in a study of CBD versus placebo for symptom management in patients with advanced cancer (MEDCAN-1).

Methods We reviewed the clinical records of all patients enrolled in the MEDCAN-1 Study (CBD vs placebo) at days 14, 28 and 56 of study follow-up, for evidence of disease progression. The proportion of participants with disease progression by treatment arm at each time point was compared, as was survival between both groups from study entry to the censor date (end of study period) and the effect of treatment arm and disease progression status on survival.

Results Of the 135 patient records assessed, 128 were included in the final analysis. 36% (n=46) had progressive disease documented at day 28, rising to 49.2% (n=63) by day 56. No significant difference in disease progression was noted between the two groups at days 14 (p=0.33), 28 (p=0.67) or 56 (p=0.50). There was no difference in survival between both groups from study entry to censor date (p=0.38). Disease progression at day 14 was highly predictive of mortality (p<0.001).

Conclusions In this substudy analysis, treatment with CBD oil did not affect disease progression or survival over the course of 56 days in patients with advanced cancer.