Objectives: The primary objective was to compare a single, 6 mL, intra-articular (IA) injection of hylan G-F 20 with placebo in patients with symptomatic knee osteoarthritis (OA). The safety of a repeat injection of hylan G-F 20 was also assessed.
Methods: Patients with primary OA knee pain were randomised to arthrocentesis plus a 6 mL IA injection of either hylan G-F 20 or placebo in a prospective, double-blind (one injector/ one blinded observer) study. Results were evaluated at 4, 8, 12, 18 and 26 weeks post-injection. The primary outcome criterion was change from baseline over 26 weeks in WOMAC A pain. Secondary outcome measures included WOMAC A1 and C, patient (PGA) and clinical observer (COGA) global assessments, and OMERACT-OARSI responder rates. A 4-week, open, repeat treatment phase evaluated safety only.
Results: Two hundred and fifty three patients (Kellgren-Lawrence Grade II or III) were randomised. Patients receiving hylan G-F 20 experienced statistically significantly greater improvement in WOMAC A pain scores (-0.15, SE 0.076, p=0.047), and several of the secondary outcome measures (WOMAC A1, PGA, and COGA), than patients receiving placebo. There was no difference between the safety results of the two groups. No increased risk of local adverse events was observed in the open, repeat treatment phase.
Conclusions: This placebo-controlled study demonstrated that, in patients with knee OA, a single 6 mL IA injection of hylan G-F 20 is safe and effective in providing statistically significant, clinically relevant pain relief over 26 weeks, with a modest difference v placebo.