A Pooled Analysis of Two Multicenter, Randomized Controlled Trials of a Single Intra-articular Injection of Gel-200 for Treatment of Osteoarthritis of the Knee

BACKGROUND AND OBJECTIVE: To perform an integrated analysis of 2 randomized controlled trials (RCTs) to assess the efficacy and safety of a single intra-articular injection of Gel-200 compared with phosphate buffered saline (PBS) for treatment of osteoarthritis of the knee. METHODS: Data from the intention-to-treat (ITT) populations of both RCTs were pooled for this integrated analysis. Mean changes from baseline in Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain subscores were assessed using a longitudinal model; treatment differences were compared between intra-articular Gel-200 and PBS injections. Analyses included secondary outcome measures repeated at individual time points. The safety populations of both RCTs were pooled for an integrated safety analysis to compare adverse events (AEs). RESULTS: The pooled ITT population included 1184 subjects (649 Gel-200; 535 PBS); demographic characteristics were similar between treatment groups. Mean improvements in pain subscores from baseline to week 12 were −24.7 mm in Gel-200 and −21.8 mm in PBS groups, a statistically significant treatment group difference of −2.9 mm (P = .047). From weeks 3 to 26, mean improvements from baseline in pain subscores were −23.8 mm with Gel-200 and −20.8 mm with PBS; this treatment group difference of −3.0 mm was statistically significant (P = .017). The rate of AEs was similar between Gel-200 and PBS treatment groups. CONCLUSION: This integrated analysis demonstrated the efficacy of a single intra-articular injection of Gel-200 compared with PBS for treatment of osteoarthritis of the knee over 26 weeks without major safety concerns. TRIAL REGISTRATION: NCT00449696 and NCT00450112.