Effect of a combination of C. longa and B. serrata extracts on hand osteoarthritis. Results of a double-blind, randomized, placebo-controlled, multicenter trial.

Objective: To evaluate the efficacy and safety of a combination of patented C. longa and B. serrata extracts (CBTIL) in patients with hand osteoarthritis compared with placebo.

Design: This 3-month, multicentre, randomized, double-blind, placebo-controlled study enrolled patients with symptomatic hand osteoarthritis, with a body mass index ≤ 35 Kg/m, and who met the American College of Rheumatology criteria for osteoarthritis of the hand (CUBO/NCT05570123). Participants received either two tablets of CBTIL or two placebo tablets per day. The primary endpoint was the difference in pain change on the visual analog scale between baseline and month 3. Secondary outcomes included the number of painful and swollen joints, functional score, quality of life, patient global assessment, grip strength, analgesic consumption, and treatment tolerance.

Results: 162 patients were randomly assigned to receive CBTIL (n=83) or placebo (n=79). In the Intention-to-treat analysis, the mean decrease (indicating pain relieve) from baseline to month 3 on the pain scale (primary endpoint) was -24.7 mm (95% Confidence Interval (CI) [-30.7 to -18.7]) in patient assigned to CBTIL group and -16.2 mm (95% CI [-22.5 to -9.9]) in patients assigned in placebo group (Difference between groups: -8.5 mm (95% CI [-16.4 to -0.6]; p = 0.03). At 3 months, the patient's global assessment (-9.6 mm [95% CI -16.9 to -2.2]), the percentage of patients achieving an acceptable symptom status (PASS) (Odd ratio (OR) 1.9 [95% CI 1.0 to 3.8]), Short Form-36 (SF-36) pain (7.1 units [95% CI 1.7 to 12.4]), and SF36 health change (6.7 units [95% CI 1.2 to 12.2]) were significantly improved by CBTIL compared to placebo. Other outcomes did not significantly differ between the two groups. No significant difference was observed regarding adverse events between the groups.

Conclusions: CBTIL relieves pain in patients with hand osteoarthritis. Together with its safety, this clinically relevant symptomatic effect suggests that CBTIL may be an alternative to oral NSAIDs and analgesics for managing symptomatic hand osteoarthritis.