Non-animal stabilized hyaluronic acid (NASHA) is a novel hyaluronan (HA) preparation with a 4-week intra-articular half-life. This study compared the efficacy of a single injection of NASHA with placebo in patients with osteoarthritis (OA) of the knee.
This was a 26-week randomized, double-blind, multicenter study of a single intra-articular knee injection with either NASHA or placebo (saline). Assessments included the Western Ontario McMasters Universities osteoarthritis index (WOMAC, Likert Scale) and patients' overall global disease status. A positive response was defined as a reduction in WOMAC pain score for the study knee of 40% from baseline with a minimum improvement of > or =5 points.
A total of 346 (NASHA 172; placebo 174) patients were treated. WOMAC scores and quality of life were improved in both the NASHA and placebo groups. For the overall population, there were no statistically significant between-group differences in response rates for any efficacy parameters. In patients with OA confined to the knee (N=216), a greater response to NASHA than placebo was observed at week 6 (P=0.025). There were few treatment-related events.
NASHA was not superior to placebo for the primary efficacy analysis. However, these data may be confounded by the inclusion of patients with OA at other sites, as significant benefits over placebo were found among patients with OA confined to the knee. Future trials of OA that examine a local therapy might need to consider restricting the study population to those patients having OA of only the signal joint.