An international, multicentre, double-blind, randomized study (DISSCO): effect of diacerein vs celecoxib on symptoms in knee osteoarthritis.

OBJECTIVE The objective of this study was to investigate whether diacerein has comparable efficacy with celecoxib in pain reduction for treatment in symptomatic knee OA patients. METHODS This randomized double-blind multicentre non-inferiority trial evaluated diacerein vs celecoxib treatment in patients with Kellgren-Lawrence grade 2-3 and pain scoring ≥4 (10-cm VAS). Patients were randomized to 6 months of treatment with diacerein 50 mg (n = 187) once daily for 1 month and twice daily thereafter, or celecoxib 200 mg (n = 193) once daily. The primary outcome was the change in WOMAC pain score (0-50 cm) at 6 months, and the secondary outcomes were WOMAC sub-scores, VAS pain score, and the OMERACT-OARSI responder rate. RESULTS In the per protocol population, the adjusted mean change from baseline in the WOMAC pain score was -11.1 ( 0.9) with diacerein (n = 140) and -11.8 (0.9) with celecoxib (n = 148). The intergroup difference was 0.7 (95% CI: -1.8, 3.2; P = 0.597), meeting the non-inferiority margin. Supportive analysis of the intention-to-treat population gave similar results. Other outcomes showed no significant difference between treatment groups. The incidence of treatment-related adverse events was low and balanced between groups, but a greater incidence of diarrhoea occurred with diacerein (10.2% vs 3.7%). Diarrhoea was considered mild-to-moderate in all but one case with complete resolution. CONCLUSIONS Diacerein was non-inferior to celecoxib in reducing knee OA pain and improving physical function. Diacerein also demonstrated a good safety profile. TRIAL REGISTRATION A multicentre study on the effect of DIacerein on Structure and Symptoms vs Celecoxib in Osteoarthritis is a National Institutes of Health (NCT02688400) and European Clinical Trial Database (2015-002933-23) registered phase III (Canada) or IV (Europe) study.