GTx, Inc. to Present New Phase IIb Clinical Trial Data for ACAPODENE™ at the Fourth International Prostate Cancer Congress

MEMPHIS, Tenn., July 16, 2004—New data from the successful Phase IIb clinical trial for ACAPODENE™ (toremifene citrate) tablets for the prevention of prostate cancer in high risk men will be presented today by Mitchell Steiner, M.D., Vice Chairman and CEO of GTx, Inc. (Nasdaq: GTXI) at the Fourth International Prostate Cancer Congress. Dr. Steiner will address medical oncologists, urologists, radiation oncologists and other leaders in the field of prostate cancer research. GTx's lead product candidate ACAPODENE™ is a nonsteroidal selective estrogen receptor modulator (SERM).

"This Congress is an ideal forum to discuss new and promising approaches impacting prostate cancer. We are happy to have this opportunity to review the recent positive results of GTx's Phase IIb clinical trial," said Dr. Steiner. "This study is a significant milestone in the prevention of prostate cancer. As the largest prospective study determining the natural history of patients with high grade prostatic intraepithelial neoplasia, it is clear that these patients are at high risk for developing prostate cancer."

Study Results

The ACAPODENE™ Phase IIb study was a double-blind, placebo-controlled, one-year clinical trial in 514 men with high grade prostatic intraepithelial neoplasia (PIN) who are at high risk for prostate cancer. The primary endpoint was the incidence of prostate cancer. This is the largest prospective study to determine the natural history of patients with high grade PIN and supports the premise that high grade PIN patients have a high risk for developing prostate cancer. The study also suggests that ACAPODENE™ may be a highly effective agent in preventing prostate cancer. The objectives of the Phase IIb clinical trial were achieved and, we believe, provide a clear signal that ACAPODENE™ can produce a statistically and clinically significant reduction of prostate cancer cumulative risk at one year in the ACAPODENE™ 20mg arm compared to placebo, 24.4% vs 31.2% respectively (p<0.05). For perspective, these results compare favorably to a previous chemoprevention trial, the Breast Cancer Prevention Trial (BCPT) using tamoxifen, where for every 100 patients 0.33 cancers were prevented per year. In comparison, ACAPODENE™ 20mg prevented 6.8 cancers for every 100 patients treated in the Phase IIb clinical trial. Furthermore, the data appears to suggest that the longer men with high grade PIN are treated with ACAPODENE™ , the greater the likelihood that their risk of prostate cancer is reduced. This is evidenced by the fact that patients in the study who had a negative prostate cancer biopsy after 6 months of treatment had a risk reduction of 48% after a full 12 months of treatment (p=0.045). Additionally, those men in the study who developed prostate cancer while being treated with GTx's ACAPODENE™ had no difference in tumor grades with a trend toward even lower grades compared to those patients who developed prostate cancer during the study while on placebo. The study demonstrated that ACAPODENEÔ was well tolerated by patients compared to placebo and Serious Adverse Events were comparable to placebo (11% placebo and 7% ACAPODENE™ 20mg). The most common drug related adverse events were similar to placebo and included headache (6% placebo and 2% ACAPODENE™ 20mg), fatigue (3% placebo and 5% ACAPODENE™ 20mg), hot flashes (3% placebo and 2% ACAPODENE™ 20mg) and nausea (4% placebo and 1% ACAPODENE™ 20mg). Following discussions with the Food and Drug Administration (FDA), GTx will initiate a Phase III clinical trial to confirm the positive findings of its Phase IIb study.

The Fourth International Prostate Cancer Congress Co-Chair, Oliver Sartor, MD, Director, Stanley S. Scott Cancer Center and Chief, Hematology/Oncology Section of Louisiana State University, stated that "In fact, this study puts to rest the controversy about high grade PIN - high grade PIN patients are at high risk for prostate cancer." Dr. Sartor continued by saying, "I am very encouraged by the ACAPODENE™ Phase IIb data and I am impressed with the reduction in prostate cancer following repeat biopsies as well as the low toxicity of ACAPODENE™."

David Price, M.D., a lead Investigator for the ACAPODENE™ Phase IIb study stated, "As a physician, it is currently frustrating that we are not armed with a therapy to prevent the development of prostate cancer in a patient diagnosed with high grade PIN when we know that half of these men will have cancer within a few years."

About PIN
High grade PIN has been established as 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 subjected to repeat prostate biopsies.

About ACAPODENE™
Toremifene is a nonsteroidal SERM, a small molecule that binds and selectively modulates the estrogen receptor. SERMs have been shown to block estrogen receptors in the prostate. GTx has licensed the right to develop, market and distribute toremifene citrate, the active ingredient of ACAPODENE™ tablets, worldwide in the field of prevention and treatment of prostate cancer from Orion Corporation, Finland.

About Prostate Cancer
In the United States, there is estimated to be over 230,000 new prostate cancer cases and 30,000 prostate cancer deaths this year. This makes prostate cancer the most commonly diagnosed cancer and the second leading cause of cancer-related deaths in men in the United States.

About GTx
GTx is a biopharmaceutical company dedicated to the discovery, development and commercialization of therapeutics primarily related to the treatment of serious men's health conditions. GTx's drug discovery and development programs are focused on small molecules that selectively modulate the effects of estrogens and androgens. GTx currently has two product candidates that are in human clinical trials. The company is developing ACAPODENE™ , its most advanced product candidate, through clinical trials for two separate indications: (1) its now completed Phase IIb clinical trial for the reduction in the incidence of prostate cancer in high risk men with precancerous prostate lesions and planned initiation of a Phase III clinical trial (2) a pivotal Phase III clinical trial for the treatment of serious side effects of advanced prostate cancer therapy. GTx is developing its second product candidate, andarine, and other specified backup compounds, with its partner, Ortho Biotech Products, L.P., a subsidiary of Johnson & Johnson. It is currently anticipated that andarine will be entering a planned Phase II clinical trial later this year. GTx retains all rights to the discovery, development, and commercialization of the rest of its SARM program including its other specific product candidates ostarine, prostarine and andromustine.

Forward Looking Statement
This press release contains forward-looking statements, including, without limitation, statements related to GTx's current and anticipated clinical trials and research and development programs. These forward-looking statements are based upon GTx's current expectations. Forward-looking statements involve risks and uncertainties. GTx's actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of these risks and uncertainties, which include, without limitation, risks that neither GTx nor its partner will be able to commercialize its product candidates if preclinical studies do not produce successful results or clinical trials do not demonstrate safety and efficacy in humans; if third parties do not manufacture the Company's product candidates in sufficient quantities and at an acceptable cost, clinical development and commercialization of its product candidates would be delayed; use of third-party manufacturers may increase the risk that the Company will not have adequate supplies of its product candidates; if third parties on whom the Company relies do not perform as contractually required or expected, the Company may not be able to obtain regulatory approval for or commercialize its product candidates; the Company is dependent upon collaborative arrangements to complete the development and commercialization of some of its product candidates, and these collaborative arrangements may place the development of its product candidates outside its control, may require it to relinquish important rights or may otherwise be on terms unfavorable to the Company; and if the Company is not able to obtain required regulatory approvals, the Company will not be able to commercialize its product candidates. The annual report filed on Form 10-K with the U.S. Securities and Exchange Commission on March 26, 2004 contains under the heading "Additional Factors That Might Affect Future Results" a more comprehensive description of these and other risks to which GTx is subject. GTx expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any forward-looking statements contained herein to reflect any change in its expectations with regard thereto or any change in events, conditions or circumstances on which any such statements are based.