GTx Inc. priced its initial public offering of 5.4 million shares at $14.50 per share - above the middle range of its $13 to $15 estimate in January - raising $78.3 million.
The Memphis, Tenn.-based firm, still in an SEC-imposed quiet period, began trading Tuesday, with its stock (NASDAQ:GTXI) falling $1.60, or 11 percent, to close at $12.90, after rising as high as $16.
In a Phase III trial is GTx's lead product, Acapodene (toremifene citrate), an oral therapy for reducing skeletal fractures and other complications of androgen-deprivation therapy in men with prostate cancer. The 24-month, placebo-controlled study testing Acapodene tablets was expected to enroll 1,200 patients, GTx said late last year. (See BioWorld Today, Nov. 11, 2003.)
Androgen deprivation is the standard therapy for prostate cancer and involves either the surgical removal of the testes or treatment with drugs, such as Abbott Park, Ill.-based Abbott Laboratories' Lupron (leuprolide) or London-based AstraZeneca plc's Zoladex (goseralin), both of which are luteinizing hormone-releasing hormone (LHRH) agonists to stop the production of testosterone.
Acapodene, a non-steroidal small molecule, is aimed at relieving the side effects of LHRH agonists, which include bone loss leading to osteoporosis and skeletal fractures, hot flashes and gynecomastia, or abnormally large breasts.
By binding and selectively modulating the estrogen receptor, Acapodene - one in a class of drugs known as SERMs - stimulates estrogen receptors in bone and blocks estrogen receptors in the breast, as well as, possibly, the prostate.
The Phase III trial is pivotal, and GTx has Acapodene in a Phase IIb study for the reduction in the incidence of prostate cancer in men with precancerous prostate lesions. In the early stages of development is GTx's second candidate, Andarine, a first-in-class selective androgen receptor modulator, for the muscle-wasting weight loss, or cachexia, that occurs from various types of cancer.
GTx said in November that a Phase II dose-finding trial for cachexia caused by non-small-cell lung cancer was expected in the first half of 2004.