The efficacy and safety of S-flurbiprofen plaster in the treatment of knee osteoarthritis: a phase II, randomized, double-blind, placebo-controlled, dose-finding study.

backgroundNonsteroidal anti-inflammatory drug (NSAID) patches are convenient for use and show much less gastrointestinal side effects than oral NSAIDs, whereas its percutaneous absorption is not sufficient for the expression of clinical efficacy at satisfactory level. S-flurbiprofen plaster (SFPP) has shown dramatic improvement in percutaneous absorption results from animal and clinical studies. In this study, the efficacy and safety of SFPP were compared with placebo in patients with knee osteoarthritis (OA) to determine its optimal dose. This was a multicenter, randomized, double-blind, parallel-group comparative study. PATIENTS AND

methodsEnrolled 509 knee OA patients were treated with placebo or SFPP at 10, 20, or 40 mg applied on the affected site once daily for 2 weeks. The primary endpoint for efficacy was improvement in knee pain on rising from the chair assessed by visual analog scale (VAS). The other endpoints were clinical symptoms, pain on walking, and global assessment by both investigator and patient. Safety was evaluated by observing adverse events (AEs).

resultsVAS change in knee pain from baseline to trial end was dose-dependent, least squares mean was 29.5, 31.5, 32.0, and 35.6 mm in placebo and SFPP 10, 20, and 40 mg, respectively. A significant difference was observed between placebo and SFPP 40 mg (

conclusionClinically relevant pain relief was observed in all groups including placebo. Especially 40 mg showed remarkable pain relief in not only primary endpoint but also all the other endpoint with significant differences over placebo. The safety profile of SFPP 40 mg was not different from that of placebo. Therefore, 40 mg was determined as the optimal tested dose.