Hyaluronan (HA) has recently been approved in the United States for management of pain in osteoarthritis (OA) of the knee and is the first biological available for use in OA. To better understand the therapeutic role of HA, this review focuses on comparative clinical trial data.
Literature reports of clinical trials comparing HA with placebo, nonsteroidal anti-inflammatory drugs, and intra-articular corticosteroids were reviewed. The pivotal US trial evaluating HA efficacy and safety was summarized.
Over the past decade, 5 of 8 controlled clinical trials demonstrated HA was superior to placebo in relieving the pain of OA. A sixth trial showed improvement in a subset of older patients with more severe disease. Comparison of HA with corticosteroids showed equal pain relief in the first few weeks after therapy, with HA demonstrating more sustained benefit up to 60 days. In the recent US trial, HA was statistically superior to placebo and at least as effective as naproxen in providing analgesia. In all trials reporting adverse effects, the primary adverse effect with HA was pain at the injection site.
HA appears effective in relieving the pain of OA of the knee and provides a relatively safe alternative for patients for whom conventional therapy has failed.