Treatment of knee osteoarthritis with a new formulation of a fixed-dose combination of glucosamine sulfate and bovine chondroitin: a multicenter, randomized, single-blind, non-inferiority clinical trial

Objectives To compare the efficacy and safety of a new formulation of a fixed dose combination of glucosamine sulfate (GS; 1500 mg) and bovine chondroitin sulfate (CS; 1200 mg) versus the reference product (RP) in patients with knee osteoarthritis (OA). Methods In this multicenter, randomized, single-blind trial, 627 patients with knee osteoarthritis (OA)—Kellgren-Lawrence grades 2 or 3 and mean score ≥ 40 mm in the WOMAC pain subscale—were randomized to receive GS/CS or the RP for 24 weeks. The primary efficacy endpoint was the absolute change in WOMAC pain subscale score. The secondary endpoints included the following: WOMAC total and subscale scores, overall assessment of the disease by the patient and the investigator, SF-12 score, OMERACT-OARSI response rate to the treatment, and rescue medication use. Results Mean reductions of WOMAC pain score were − 35.1 (sd = 23.2) mm in the GS/CS group and − 36.5 (sd = 24.9) mm in the RP group. The difference between the adjusted means of both treatments confirmed the non-inferiority of GS/CS versus the RP. Improvement was observed in pain, stiffness, physical function and total WOMAC score, as well as in overall OA assessment by the patient and the investigator for both groups. No improvement was observed in SF-12. The rate of OMERACT-OARSI responders was 89.4% in GS/CS group and 87.9% in the RP group. Headache and changes in glucose tolerance were the most frequent treatment-related adverse events. Conclusions The new formulation of a fixed-dose combination of glucosamine sulfate and bovine chondroitin sulfate was non-inferior to the RP in symptomatic treatment of knee OA, with a high responder rate and good tolerability profile. Trial registration ClinicalTrials.gov; Registration number NCT02830919; Date of registration: July 13, 2016; First randomization date: December 05, 2016).