Study confirms safety of diclofenac gel for actinic keratosis.

AMSTERDAM -- Diclofenac 3% gel was well tolerated and showed an excellent safety profile for treatment of multiple actinic keratoses in a primary care postmarketing safety surveillance study.

The study, conducted in 140 primary care practices in the United Kingdom, showed no severe treatment-related adverse events in 450 treated patients. The most common adverse events were mild to moderate dry skin, itching, and redness, each occurring in 16%-20% of patients, Dr. Ron Higson reported at the 11th World Congress on Cancers of the Skin.

Severe versions of these side effects occurred in fewer than 4% of patients, added Dr. Higson of Clitheroe (England) Health Centre.

Participants in this observational study were instructed to apply diclofenac 3% gel (Solaraze) twice daily for 12 weeks to areas of actinic keratoses (AKs) in accord with the product labeling.

The topical nonsteroidal anti-inflammatory drug is licensed for treatment of AKs in the United States, United Kingdom, and some other European countries. Patients were assessed during office visits at baseline and at weeks 6, 12, and 16.

Although this was designed primarily as a safety study, there was a secondary efficacy end point consisting of change over time in the longest AK axis from each patient's three largest AKs.

The mean reduction in the size of AKs located on the head, face, or neck was 2.8 mm at week 6 and 6.4 mm at the week 16 follow-up visit, Dr. Higson reported at the congress, which was cosponsored by the Skin Cancer Foundation and Erasmus University, Rotterdam, the Netherlands.

The study was funded by Shire Pharmaceuticals.

Dr. Eggert Stockfleth commented that diclofenac gel's two major advantages are its safety--the topical agent induces only very mild erythema and has no systemic effects-and the fact that it treats not only visible AK lesions but also what he calls the "field cancerization"--the underlying dysplasia that gives rise to new AKs and eventually to skin cancers.

The drug's mechanism of action is believed to involve inhibition of angiogenesis along with stimulation of apoptosis, added Dr. Stockfleth, director of the skin cancer center at Charite University Hospital, Berlin.

BY BRUCE JANCIN

Denver Bureau