A multicenter, randomized controlled trial comparing a single intra-articular injection of Gel-200, a new cross-linked formulation of hyaluronic acid, to phosphate buffered saline for treatment of osteoarthritis of the knee.

OBJECTIVE To compare the safety and efficacy of a single intra-articular (IA) injection of a new cross-linked hyaluronic acid product, Gel-200, with phosphate buffered saline (PBS, control) in a multi-center randomized controlled trial in patients with symptomatic osteoarthritis (OA) of the knee. DESIGN Patients were randomized 2:1 to receive a single injection of Gel-200 or PBS, after joint aspiration. The primary measure of effectiveness was Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscores by 100-mm Visual Analog Scale (VAS); secondary outcomes included: total WOMAC, physical function, and stiffness subscores; patient and physician global assessments of disease activity, Outcome Measures in Rheumatology Clinical Trials and Osteoarthritis Research Society International (OMERACT-OARSI) strict responders, as well as safety of Gel-200. RESULTS Of 379 patients randomized, safety was evaluated in 377 and efficacy in 375 (98.9% randomized) in the intent-to-treat population. Effectiveness of Gel-200 by WOMAC pain subscores was statistically significant at week 13 (P=0.037). Mean improvements from baseline in WOMAC pain subscores consistently favored Gel-200 at each visit. Effectiveness of Gel-200 treatment was statistically significant over weeks 3-13 by WOMAC total score, physical function, and physician global evaluations (P<0.05). The number of "strict" OMERACT-OARSI responders was statistically significant from weeks 6 to 13 (P=0.022). Adverse events were not significantly different between treatment groups, including serious adverse events considered related to study treatment. CONCLUSIONS This trial demonstrated that a single injection of Gel-200 was well tolerated and relieved pain associated with symptomatic OA of the knee over 13 weeks. TRIAL REGISTRATION NUMBER ClinicalTrials.gov NTC 00449696.