Effectiveness and safety of polyacrylamide hydrogel injection for knee osteoarthritis: results from a 12-month follow up of an open-label study.

OBJECTIVE: There are few effective osteoarthritis (OA) therapies. A novel injectable polyacrylamide hydrogel (iPAAG) previously demonstrated efficacy and safety up to week 26 in an open-label study of knee OA. Here we report longer-term effectiveness and safety data. METHODS: This multi-centre, open-label study included patients with symptomatic and radiographic knee OA. Primary outcome was WOMAC pain (0-100 scale) at 13 weeks, and patients continued to 26 weeks before entering a further 26-week extension phase. Secondary efficacy outcomes included WOMAC stiffness and function subscales, Patient Global Assessment (PGA) and proportion of OMERACT-OARSI responders. Safety outcomes were adverse events (AEs). RESULTS: 49 participants (31 women, mean age 70) received an ultrasound-guided, intra-articular injection of 6 ml iPAAG; 46 completed the extension phase to 52 weeks. There was a significant reduction in the WOMAC pain score from baseline to 52 weeks (- 17.7 points (95% CI - 23.1; - 12.4); p < 0.0001). Similar sustained improvements were observed for WOMAC stiffness (11.0 points; 95% CI - 17.0; - 4.9), physical function (18.0 points; 95% CI - 19.1; - 10.6), and PGA (16.3 points; 95% CI - 23.1; - 9.4). At 52 weeks 62.2% of patients were OMERACT-OARSI responders. From 26 to 52 weeks, 8 adverse effects (AE), including 1 serious AE (cerebrovascular accident) were reported in 5 subjects. None of the new adverse events were thought to be device related. CONCLUSION: This open-label study suggests persistent benefits and safety of iPAAG through 52 weeks after a single injection. TRIAL REGISTRATION: Clinicaltrials.gov NCT04179552.

Polyacrylamide gel versus hyaluronic acid for the treatment of knee osteoarthritis: a randomised controlled study.

OBJECTIVES: To assess non-inferiority of intra-articular injectable polyacrylamide hydrogel (iPAAG) to hyaluronic acid (HA) on symptomatic benefit in individuals with knee osteoarthritis (OA). METHODS: This randomised, controlled, multi-centre trial recruited adults with symptomatic and radiographic knee OA from 3 clinical rheumatology sites in Denmark; two private clinics and one public hospital department. Participants were randomised 1:1 to receive a single intra-articular 6 mL injection of either HA or iPAAG on an outpatient basis. Primary outcome was change from baseline in WOMAC pain subscale after 26 weeks. Secondary outcomes were changes from baseline in WOMAC stiffness and physical function subscales, patients' global assessment of disease impact, EuroQoL-5D-5L, and proportion of positive OMERACT-OARSI responders after 26 and 52 weeks. RESULTS: 239 adults were randomised: 120 to HA and 119 to iPAAG. For the primary outcome, the least squares mean changes in WOMAC pain were -14.8 (95% CI: -18.0 to -11.7) for HA and -18.5 (95% CI: -21.7 to -15.4) for iPAAG; group difference: 3.7 (95% CI: -0.7 to 8.1). The lower boundary of the 95% CI respected the pre-specified non-inferiority margin of 9 WOMAC pain points. No statistically significant differences were observed for the secondary outcomes. For HA, 9 participants (7.6%) reported 13 adverse device effects (ADEs). For iPAAG, 35 participants (28.9%) reported 41 ADEs. All ADEs were mild/moderate, with no serious ADEs reported. CONCLUSIONS: iPAAG was found to be as effective and safe as HA for treatment of knee OA symptoms for at least 1 year after a single injection.

Efficacy and safety of four doses of lumiracoxib versus diclofenac in patients with knee or hip primary osteoarthritis: a phase II, four-week, multicenter, randomized, double-blind, placebo-controlled trial.

OBJECTIVE: To compare the efficacy and tolerability of the novel cyclooxygenase 2-selective inhibitor lumiracoxib with placebo and diclofenac in osteoarthritis (OA). METHODS: Adults (n=583) with knee or hip OA were randomized to receive for 4 weeks lumiracoxib 50, 100, or 200 mg twice daily or 400 mg once daily; placebo; or diclofenac 75 mg twice daily. Efficacy assessments included overall joint pain intensity and Western Ontario and McMaster Universities Osteoarthritis Index subscales; tolerability was evaluated by adverse event and physician reporting. RESULTS: All lumiracoxib doses were superior to placebo in relieving pain, improving stiffness, and improving physical function after 4 weeks. At study endpoint, pain relief was comparable among all lumiracoxib dosages and similar to diclofenac. Lumiracoxib tolerability was superior to diclofenac and comparable to placebo. CONCLUSION: Lumiracoxib provides predictable and sustained relief from pain, stiffness, and impaired physical function in OA. Lumiracoxib shows clinically comparable efficacy and superior tolerability to diclofenac.