PHASE IV STUDIES COMPARING FOREIGN CONTRACEPTIVES
Executive Summary
PHASE IV STUDIES COMPARING FOREIGN CONTRACEPTIVES with U.S. products will be sponsored under a proposed research initiative by the National Institute of Child Health and Human Development (NICHD). Up to $3.5 mil. would be provided over the next two years to fund studies comparing the safety of contraceptives approved in foreign countries with similar U.S. approved products. NICHD proposes to support Phase IV, post-marketing surveillance that includes: metabolic studies of foreign-marketed products such as desogestrel, norethindrone enanthate, and depomedroxyprogesterone acetate (DMPA); epidemiologic studies on the relationship between reproductive system cancers and exposure to progestins not available in the U.S.; clinical trials comparing intrauterine devices (IUDs) available outside the U.S. with Alza's Progestasert IUD available in the U.S.; and clinical trials comparing the degree to which barrier contraceptives reduce sexually transmitted diseases. Foreign contraceptives found superior to products currently available in the U.S. "may be introduced into the U.S. in an accelerated fashion," the initiative states. The studies of foreign-approved contraceptive products are among 22 contraceptive reseach plans for fiscal years 1988-1990 outlined in NICHD's Contraceptive Development Initiative. NICHD presented the report at a recent meeting of NICHD's Advisory Council. NICHD said likely study sites would include England, Scandinavia, Western Europe, Southeast Asia and Africa. Studies would be funded by contracts through the World Health Organization (WHO), Family Health International, or an American-based School of Public Health. Another area NICHD has targeted for potential support is the identification and characterization of reproductive hormone antigens that evoke immune responses to fertility. The report notes that "recent studies have shown the existence of antigens of male or female gametes or reproductive hormones which evoke immune reactions causing markedly reduced fertility or even sterility." NICHD added: "Monoclonal antibodies have been identified that react with antigenic determinants restricted solely to reproductive tissues and these might serve as vaccine candidates." The report noted that in several studies, "passive immunization using such antibodies resulted in experimentally induced infertility." NICHD is currently sponsoring a Phase II clinical trial of Research Triangle Institute's biodegradable contraceptive implant Capronor. The study of the biodegradable contraceptive implant involves 40 women and began in 1986 at the University of California at San Francisco. Capronor consists of a tube, implanted subcutaneously, that releases levonorgestrel for more than one year. NICHD, in collaboration with WHO, also plans a Phase I trial of levonorgestrel ester oxime as a long-acting injectable contraceptive. The study is slated to begin this year or in 1989. Research on the long-acting progestins was first proposed at a June 1985 meeting of the NICHD's Advisory Council.