Non-Inferiority of a Single Injection of Sodium Hyaluronate Plus Sorbitol to Hylan G-F20: A 6-Month Randomized Controlled Trial.

INTRODUCTION: Several viscosupplement treatments are available for patients suffering from painful osteoarthritis (OA) of the knee, but few comparative clinical trials have been conducted. The primary objective of the trial was to demonstrate the non-inferiority of Synolis VA (80 mg hyaluronic acid and 160 mg sorbitol) (Group HA1) to Synvisc-One (48 mg hylan GF-20) (Group HA2) at Day 168 in terms of pain relief efficacy in patients with knee OA (Kellgren and Lawrence radiological stage II or III) in whom oral treatment with analgesics, NSAIDs or weak opioids provided insufficient clinical responses or were poorly tolerated. METHODS: This was a prospective, multicentre, comparative, randomized, double-blinded trial comparing the two previously indicated viscosupplements, HA1 and HA2. The average VAS pain score (1-100) was 62.5 at baseline (Day 0). The patients were randomized into two parallel groups at Day 0 and followed until Day 168. They received one injection of either HA1 or HA2. The primary end point was the evolution of the Western Ontario and McMaster University (WOMAC) pain index at D168 in the groups. One of the secondary end points was the daily assessment of this index by the patient for 7 days following the injection and thereafter at Day 14. The other secondary end points were the WOMAC pain, stiffness, function and total scores assessed at Day 28, Day 84 and Day 168. At Day 168, efficacy and satisfaction were assessed by the evaluator and by the patient using a Likert scale (7 points). Moreover, the number of strict responders in each group was evaluated according to the The Osteoarthritis Research Society International (OARSI) Standing Committee for Clinical Trials Response Criteria Initiative and the Outcome Measures in Rheumatology (OMERACT) criteria (OMERACT-OARSI). The per protocol (PP) population was used for the primary analysis. RESULTS: A total of 202 patients were randomized. The patients were predominantly female (66%). The median age of the whole population was 65 years, and the median body mass index was 27.4 kg/m(2). No statistically significant differences between the two treatment groups were observed for any of the demographic criteria. At Day 168, 197 had had no protocol violations (94 in the HA1 group and 103 in the HA2 group). The WOMAC pain score decreased in the two groups: - 29.2 ± 24.1 (SD) in the HA1 group and - 31.6 ± 25.5 (SD) in the HA2 group, confirming the non-inferiority of Synolis VA (P = 0.57 for the difference between groups). Regarding the secondary end points, no significant difference was observed at Day 14, Day 28, Day 84 or Day 168 for all the outcomes except stiffness at Day 28 (P = in favour of treatment received in HA2). The rate of responders was comparable between the two groups: 79% for HA1 and 77% for HA2. Both products were well tolerated. Serious adverse events were reported by four patients in the HA1 group and 3 in the HA2 group. CONCLUSION: In this trial, we confirmed the non-inferiority of Synolis VA compared to Synvisc-One at Day 168 according to the WOMAC pain score. Safety was satisfying and comparable in the two groups. TRIAL REGISTRATION: 2017-A00034-49.