October 19, 2004 - SEATTLE - Toremifene citrate (trade name Acapodene), a drug currently used to treat breast cancer in women, reduces the incidence of prostate cancer for men at high risk for the disease.
Acapodene, lead product candidate of the GTx company, is a nonsteroidal selective estrogen receptor modulator (SERM).
In a study presented today at the American Association for Cancer Research Third Annual International Conference on Frontiers in Cancer Prevention Research, scientists found that patients at all dose levels for toremifene had a lower cumulative incidence of cancer after 12 months of treatment, with the 20 mg dose contributing the greatest effect.
All participating patients had high-grade prostatic intraepithelial neoplasia or PIN, characterized by abnormal cells in the lining of the prostate ducts. Early research suggests that most patients with high-grade PIN will develop prostate cancer within 10 years, but more research is needed to confirm those findings.
"For men with high-grade PIN, the prospect of developing prostate cancer is a very real possibility," said Dr. Mitchell S. Steiner,
Mitchell Steiner MD, FACS, Vice-Chairman and CEO of GTx, Inc.
"Fortunately, these results offer a promising new preventive approach to prostate cancer treatment. A chemopreventive agent like toremifene is a first step toward the possibility of stopping prostate cancer before it starts and gives patients and doctors a chance to fight this pervasive disease."
In a multi-center, double-blind study, 514 patients with high-grade PIN and no cancer, determined by pre-study biopsies, were randomized to placebo or toremifene 20 mg, 40 mg or 60 mg given orally once a day. Patients were re-biopsied at six and 12 months.
During the study, 24.4 percent of patients taking 20 mg dose of toremifene were diagnosed with prostate cancer versus 31.2 percent of patients taking placebo. Among the patients who completed 12 months of treatment, the reduction in prostate cancer incidence was 48 percent for patients receiving 20 mg of toremifene compared to those in the placebo group.
For men who developed prostate cancer, those treated with toremefine had similar tumor grades to those of placebo patients. The drug was "well tolerated." The number of adverse events "were similar between those patients receiving Acapodene compared to placebo."
GTx plans to initiate a Phase III clinical trial in 2004 following discussions with the Food and Drug Administration (FDA).
About PIN
High grade PIN is a premalignant lesion that has strong potential to progress to prostate cancer. In the United States, approximately 1,300,000 prostate biopsies are performed annually to detect 230,000 new cases of prostate cancer. There are approximately 115,000 new cases of high grade PIN diagnosed each year, representing an estimated 9% of prostate biopsies. Currently, patients diagnosed with high grade PIN have to be followed closely by their urologist and are checked by means of repeat prostate biopsies.
About prostate cancer
Prostate cancer is the most commonly diagnosed cancer in America among men. With an estimated 220,000 new cases diagnosed each year, one in every five men will get prostate cancer during his lifetime. African-American men are at special risk for the disease. In fact, the incidence rate in African-Americans is 60 percent higher than that in white males and double the mortality rate. An estimated 29,900 American men lose their lives to prostate cancer each year.
