- The effects of STA-5312 on the developing human fetus are unknown. Therefore, women of childbearing potential (defined as women over 50 years of age or history of amenorrhea for <12 months prior to study entry) must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a female subject become pregnant or suspect she is pregnant while participating in this study, she should inform the treating physician immediately.