A phase 2 clinical trial published in the journal Cancer Medicine finds that cannabidiol (CBD) may help reduce joint pain caused by aromatase inhibitor therapy in women with hormone receptor-positive breast cancer.
Researchers from the Holden Comprehensive Cancer Center and the University of Michigan School of Public Health enrolled 39 women experiencing musculoskeletal symptoms related to aromatase inhibitors (AIMSS). Participants received pharmaceutical-grade CBD (Epidiolex), titrated to 100 mg twice daily over four weeks and continued for a total of 15 weeks.
The study’s primary endpoint was a reduction of at least two points in worst pain from baseline to the end of treatment. By week 15, 17 of the 39 participants (44%) met this goal. Among all patients, worst pain scores improved an average of 0.13 points per week (p < 0.001), with a 1.95-point average reduction overall. Patients who completed the full treatment protocol experienced an even greater reduction, averaging 2.36 points.
Although five participants discontinued due to side effects and six dropped out for other reasons, the authors concluded that CBD was generally safe and well tolerated. The findings support further investigation into CBD as a treatment for AIMSS, particularly to identify which patients may benefit most.
The study’s full abstract can be found below:
Abstract
Introduction: Aromatase inhibitor (AI) therapy reduces breast cancer recurrence risk. However, some patients stop treatment early because of AI-associated musculoskeletal symptoms (AIMSS). AIMSS is due in part to systemic inflammation. Cannabidiol (CBD) has anti-nociceptive and anti-inflammatory properties, making it a potential treatment option for AIMSS.
Methods: Women with stage 0-3 hormone receptor-positive breast cancer experiencing AIMSS enrolled in this phase 2 clinical trial. Patients received CBD (Epidiolex), titrated over 4 weeks to 100 mg BID, for a total of 15 weeks. Patient-reported outcomes were collected serially. The primary endpoint was the number of patients with at least a 2-point reduction in worst pain from baseline to 15 weeks. Statistical analysis was completed using paired t-tests and linear mixed models.
Results: Of 39 eligible patients, 28 completed protocol-directed study treatment. Eleven discontinued treatment due to toxicity (n = 5) or per patient preference (n = 6). Seventeen of 39 patients met the primary endpoint (43.6%, 95% CI [28%, 60%]). Worst pain improved 0.13 per week of treatment (p < 0.001) for all patients; average improvement in worst pain was 1.95 points at the end of 15 weeks. Of the 28 patients who completed the study, average reduction in worst pain was 2.36 points (95% CI [-3.22, -1.49]) between baseline and Week 15.
Conclusion: Treatment with CBD was safe, tolerable, and associated with improvement in joint pain for a subset of patients. Additional studies are needed to further understand the impact of CBD on AIMSS and which patients are most likely to benefit from CBD treatment.
