Conference Coverage

Cannabidiol gel for osteoarthritis knee pain gives lukewarm results


Key clinical point: Although transdermal cannabidiol gel didn’t significantly reduce knee osteoarthritis pain, there is an indication that some patients may benefit.

Major finding: Mean knee pain scores at 12 weeks fell by –2.4 for placebo, and –2.6 (P = .5) and –2.8 (P = .25) for a 250-mg and a 500-mg formulation of the gel.

Study details: A 12-week, randomized, double-blind, placebo-controlled, phase 2, multidose study involving 320 patients with osteoarthritis knee pain for at least 12 months.

Disclosures: Dr. Hunter has consulted for Flexion, Merck Serono, TissueGene, and Zynerba, and has received royalties from DJO for a patellofemoral brace.

Source: Hunter D et al. Osteoarthritis Cartilage 2018:26(1):S26. Abstract 30.



– There was no significant reduction in pain from knee osteoarthritis (OA) with the use of investigational cannabidiol (CBD) gel ZYN002 in a phase 2a trial presented at the World Congress on Osteoarthritis.

The mean reductions in baseline knee pain scores from study entry to a 12-week assessment were –2.4 for placebo and –2.6 (P = .5) and –2.8 (P = .25), respectively, for a 250-mg and a 500-mg formulation of the gel.

Dr. David Hunter, the Florance and Cope Chair of Rheumatology and professor of medicine at the University of Sydney Sara Freeman/MDedge

Dr. David Hunter

While there was a trend for benefit, it was “neither statistically or clinically significant,” reported David Hunter, MBBS, PhD.

However, he observed that a significantly (P = .016) greater number of patients who received the 250-mg dose (52.7%) were “composite responders,” compared with patients who received placebo (34.1%). A composite response was defined as at least a 30% reduction in pain, and a 20% decrease in WOMAC physical function subscale score at the last observation.

Although the percentage of composite responders was also higher than placebo with the 500-mg dose, the difference wasn’t significant (45.1% vs. 34.1%; P = .0169).

Post-hoc analyses also suggested that perhaps some patients may benefit more than others, reported Dr. Hunter, professor of medicine at the University of Sydney and the Royal North Shore Hospital, Sydney.

For example, patients with baseline pain scores or 7 or more had greater mean reduction in pain at 12 weeks with both doses of the gel combined than placebo at week 4 (–2.2 vs. –1.6; P = .029), although the difference was not significant at week 8 (–3.0 vs. –2.2; P = .05) or 12 (–3.3 vs. –2.5; P = .086).


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