Topical Therapy a New Approach to Managing Pain in Osteoarthritis?

Topical Therapy a New Approach to Managing Pain in Osteoarthritis?

By Rebekah McCallister

With increasing scrutiny of the safety of oral therapies for pain management, a topical cream may resolve some of these issues if proved safe and effective. One such therapy is currently in clinical trials, investigating the safety and efficacy of a topical agent for the treatment of patients with osteoarthritis.

Result of a phase 3 trial show that the investigational civamide cream 0.075% (cis-8-methyl-N-vanillyl-6-nonenamide; Winston), a synthetic neuropeptide-active medication that selectively depresses the activity of the type-C pain fibers, may be safe and effective for patients with mild-to-moderate pain associated with this common condition, which affects about 20 million Americans.

The 12-week, multicenter, double-blind placebo-controlled study included 695 men and women (aged 40-75 years) with osteoarthritis of the knee who were randomized to civamide cream or placebo. All patients had significant pain while taking either a cyclooxygenase (COX)-2 inhibitor or a traditional nonsteroidal anti-inflammatory drug (NSAID) for at least 1 month. Patients continued using their COX-2 or NSAIDS agent in addition to the topical or placebo therapy. Efficacy and safety evaluations were done on days 21, 42, 63, and 84.

Results showed significant improvement in all 3 primary end points—decreases in pain, improvements in physical function, and increased patient satisfaction—in the group receiving civamide cream.

The most common adverse event (9% of patients) was a transient, mild-to-moderate burning sensation at the application site. Other events included localized warmth, infections, cough, nasopharyngitis, arthralgias, and headache. No systemic absorption of the cream was detected so far.

A second phase 3 trial of the cream will begin later this year, and a long-term safety trial will be completed by mid-2005.