TESTOSTERONE INJECTABLE MALE CONTRACEPTIVE: CLINICAL TESTS

TESTOSTERONE INJECTABLE MALE CONTRACEPTIVE: CLINICAL TESTS at the University of Washington in Seattle are currently being conducted as a follow-up to recently reported trials sponsored under the auspices of the World Health Organization (WHO). The current study on testosterone enanthate began in Seattle in December of last year. It is part of a multi-center trial in a number of countries designed to test "whether hormonally induced severe oligozoospermia (equal to or less than 5 million sperm per milliliter) results in an acceptable level of contraceptive efficacy." The follow-up study is slated to involve 400-450 couples in 15-20 centers world-wide, WHO reported. At the University of Washington, the lead researcher is C. A. Paulsen. The Seattle center currently has approximately 20 men involved, and is recruiting more. Results of the initial WHO-sponsored tests on testosterone enanthate were publicized in an Oct. 22 press release from the international health organization. A full report was published in the Oct. 20 edition of The Lancet. The initial trials were designed to test the general premise of a contraceptive based on hormone-induced azoospermia in normal men. WHO concluded, according to The Lancet report, that "hormonal regimens that induce azoospermia can provide highly effective, sustained, and reversible male contraception with minimum side-effects." The first trials were not aimed at determining the merits of testosterone enanthate as a specific contraceptive candidate. "The practicality of testosterone enanthate as a contraceptive method was not investigated," the report notes. That drug was chosen in part because "the overall safety of testosterone enanthate administration has already been well established during decades of widespread clinical use." The first study at the University of Washington was supported by funds from the Contraceptive Branch of the U.S. Agency for International Development (AID) and from the National Institutes of Health,Paulsen said. Bristol-Myers Squibb provided its testosterone enanthate brand Delatestryl for the Seattle trials. Schering AG provided the hormone overseas. The WHO trials involved 271 men taking injections in 10 centers in seven countries. Of those who began, 157 (or 70%) became azoospermic (no sperm in their ejaculate). Of those 157, 114 completed the 12-month efficacy phase. During the total of 1,486 months of the efficacy phase, there was one pregnancy among the azoospermic men. Fifteen men withdrew from the study because of difficulties with the weekly injections, 27 for medical reasons (including acne, increased aggressiveness and libido, weight gain, raised packed cell volume and hemoglobin, and abnormal lipids). WHO is pursuing the male hormonal contraceptive with the objective of developing preparations that will require only three or four injections per year.