In an Australian phase IIb trial (MedCan1-CBD) reported in the Journal of Clinical Oncology, Hardy et al found that use of cannabidiol (CBD) oil did not improve symptom distress vs placebo in adult patients with advanced cancer receiving palliative care.
Study Details
The double-blind multicenter trial included 142 eligible patients with symptom distress defined as Edmonton Symptom Assessment Scale total symptom distress score (TSDS) of ≥ 10 out of 90. They were randomly assigned between February 2019 and November 2021 to receive oral CBD oil (n = 70) or placebo (n = 72) for 28 days. The TSDS contains nine components—symptoms of pain, tiredness, nausea, somnolence, shortness of breath, appetite, anxiety, and depression and overall well-being—scored on a 0 to 10 scale. CBD oil and placebo were titrated every third day over 14 days from 0.5 mL once daily to 2 mL three times a day as tolerated, corresponding to 50 mg once daily to a maximum of 200 mg three times a day; patients had the option of remaining on their selected dose of CBD oil/placebo throughout 28 days. The primary outcome measure was TSDS at day 14, with response defined as a reduction in TSDS by six or more points at day 14.
Key Findings
Among the 142 eligible patients, 58 in the CBD oil group and 63 in the placebo group reached the primary analysis point on day 14 and were included in the analysis.
Unadjusted change in TSDS from baseline to day 14 was –3.0 points (standard deviation [SD] = 15.2 points) in the CBD oil group vs –6.2 points (SD = 14.5 points) in the placebo group (P = .24).
Response at day 14 was observed in 26 (44.8%) of 58 patients in the CBD oil group vs 37 (58.7%) of 63 in the placebo group (P = .13).
All components of the TSDS improved (decreasing scores) over time in both groups, with no significant differences between groups being observed.
On the Global Impression of Change scale, proportions of patients in the CBD oil vs placebo groups who reported feeling ‘better’ or ‘much better’ were 53% vs 65% at day 14 and 70% vs 64% at day 28.
No effects of CBD oil treatment were observed for quality of life on the EORTC QLQ-C15 questionnaire or for depression or anxiety on the Depression Anxiety Stress Scale.
The median dose of patient-selected CBD oil was 400 mg per day. No difference between groups was observed in change in opioid dose; at day 14, 10 patients in the CBD oil group (17.5%) and 8 in the placebo group (12.7%) had reductions in their total daily opioid dose. No associations with study drug dose and use of benzodiazepines or antipsychotics were observed.
No significant differences were observed between the groups in terms of adverse events of special interest; trends for more frequent somnolence and abdominal pain in the CBD oil group and vomiting in the placebo group were observed. No differences were observed between groups in adverse events of special interest (and no grade ≥ 2 events), except for a greater incidence of new or worsening dyspnea in the CBD oil group (8 vs 2 patients, P = .04).
The investigators concluded, “CBD oil did not add value to the reduction in symptom distress provided by specialist palliative care alone.”
Janet Hardy, MD, FRACP, of the Mater Research Institute—University of Queensland, Brisbane, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by the Commonwealth of Australia—Medical Research Future Fund.
