- The effects of CCI-779 (temsirolimus) on the developing human fetus and newborn are unknown; for this reason and because CCI-779 (temsirolimus) may be teratogenic, patients must not be pregnant or nursing; men or women of childbearing potential must have agreed to use an effective contraceptive method prior to study entry and for the duration of study participation; since interaction with CCI-779 (temsirolimus) and oral contraceptives is possible, a barrier method should be used and oral contraceptives are not permitted; a negative pregnancy test is required prior to starting therapy for women of childbearing age; should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately