Initial data from a large, international clinical trial indicate that dutasteride (Avodart) may help prevent prostate cancer among men at higher risk for the disease, according to an April 27 report at the American Urological Association annual meeting in Chicago.

The trial, called REDUCE, compared dutasteride treatment against placebo among 8,200 men considered to be at high risk for the disease because of their elevated levels of prostate-specific antigen (PSA). All the men had received negative (clean) prostate biopsies within 6 months before joining the study.

After follow-up biopsies at 2 and 4 years, dutasteride was shown to lower the risk of prostate cancer by 23 percent compared with men taking the placebo.

Men treated with dutasteride were also found to be at no greater risk than those on placebo for developing aggressive prostate tumors. "We are very encouraged by this finding," lead investigator Dr. Gerald Andriole of the Washington University School of Medicine said in a statement. The study was funded by GlaxoSmithKline, which manufactures dutasteride.

The results are comparable to those from the NCI-funded Prostate Cancer Prevention Trial (PCPT), an earlier prevention study for prostate cancer involving a drug of the same class, finasteride (Proscar). Initial findings from PCPT suggested that finasteride decreased the risk of prostate cancer but may have increased the risk of developing more aggressive tumors. Subsequent investigations by NCI scientists and others showed that finasteride did not promote more aggressive tumors and may actually reduce their risk. Both finasteride and dutasteride are approved to treat benign prostatic hyperplasia.