<p><strong>Pregnancy</strong>: There are no clinical studies of trastuzumab emtansine in pregnant women. No reproductive and developmental toxicology studies have been conducted with trastuzumab emtansine.<br />
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Trastuzumab, a component of trastuzumab emtansine, can cause fetal harm or death when administered to a pregnant woman. In the postmarketing setting, cases of oligohydramnios, some associated with fatal pulmonary hypoplasia, have been reported in pregnant women receiving trastuzumab. Animal studies of maytansine, a closely related chemical entity of the same maytansinoid class as DM1, suggest that DM1, the microtubule inhibiting cytotoxic drug component of trastuzumab emtansine, is expected to be teratogenic and potentially embryotoxic.<br />
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Administration of trastuzumab emtansine to pregnant women is not recommended. Women who become pregnant must contact their doctor and should be advised of the possibility of harm to the fetus. If a pregnant woman is treated with trastuzumab emtansine, close monitoring by a multidisciplinary team is recommended.<br />
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<strong>Nursing Mothers</strong>: It is not known whether trastuzumab emtansine is excreted in human milk. Since many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from Kadcyla, women should discontinue nursing prior to initiating treatment with trastuzumab emtansine. Women may begin nursing 7 months after concluding treatment.</p>