Phase III Clinical Trial Results Demonstrate Toremifene Citrate 80 mg Compared to Placebo Reduced Fractures and Treated Multiple Other Estrogen Related Side Effects of ADT

GTx, Inc. (NASDAQ: GTXI) announced that results of the Phase III ADT clinical trial evaluating toremifene citrate 80 mg for the treatment of multiple side effects of androgen deprivation therapy (ADT) in men who have advanced prostate cancer were presented today during a late breaking oral session at the 2008 Annual Meeting of the American Association for Cancer Research (AACR) in San Diego. Results of the Phase III ADT clinical trial demonstrate that toremifene citrate 80 mg compared to placebo built bone and prevented fractures, reduced hot flashes, and treated other estrogen related side effects of ADT.

ADT, the most common treatment for advanced prostate cancer, is a form of hormone therapy that works by reducing testosterone and estrogen. While it is successful in stopping the progression of prostate cancer, it can result in multiple estrogen related side effects, including bone loss and increased risk of fractures, hot flashes, adverse lipid changes and increased cardiovascular risk, and gynecomastia (breast pain). Studies have shown that men on ADT are three times more likely to experience a fracture than postmenopausal women, and that when they develop a fracture, their median survival rate decreases by more than three years.

“As a medical oncologist treating prostate cancer patients, I have seen firsthand how the serious side effects of ADT not only have an impact on a man’s quality of life but can also be life threatening,” said Matthew R. Smith, MD, PhD, Director, Genitourinary Medical Oncology, Massachusetts General Hospital Cancer Center, Associate Professor of Medicine at Harvard Medical School, and Lead Investigator of the Phase III ADT clinical trial. “There are no medicines approved to treat side effects of ADT. The results of the Phase III ADT clinical trial are exciting, as they demonstrate that toremifene citrate 80 mg prevents fractures and treats other side effects of ADT.”

About the study

The two year double-blind, placebo-controlled, randomized study of 1,389 ADT patients, was conducted at approximately 150 clinical sites in the United States and Mexico. The primary endpoint was new morphometric vertebral fractures. Other key secondary endpoints included bone mineral density, lipid changes, hot flashes, and gynecomastia.

Primary endpoint

In a modified intent to treat analysis, which included all patients with at least one evaluable study radiograph and a minimum of one dose of study drug or placebo, patients receiving toremifene citrate 80 mg had approximately a 53 percent reduction in new morphometric vertebral fractures compared to placebo (p=0.03).