e, itraconazole, clarithromycin, atazanavir, indinavir, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, and voriconazole) with KADCYLA should be avoided due to the potential for an increase in DM1 exposure and toxicity. Consider an alternate medication with no or minimal potential to inhibit CYP3A4. If concomitant use of strong CYP3A4 inhibitors is unavoidable, consider delaying KADCYLA treatment until the strong CYP3A4 inhibitors have cleared from the circulation (approximately 3 elimination half-lives of the inhibitors) when possible. If a strong CYP3A4 inhibitor is coadministered and KADCYLA treatment cannot be delayed, patients should be closely monitored for adverse reactions.
8 USE IN SPECIFIC POPULATIONS
8.1 Pregnancy
Pregnancy Category D [see Warnings and Precautions (5.3)]
Risk Summary
KADCYLA can cause fetal harm when administered to a pregnant woman. There are no adequate and well-controlled studies of KADCYLA in pregnant women. No reproductive and developmental toxicology studies have been conducted with ado-trastuzumab emtansine. Nevertheless, two components of KADCYLA (trastuzumab and DM1) are known or suspected to cause fetal harm or death when administered to a pregnant woman. If KADCYLA is administered during pregnancy, or if a patient becomes pregnant while receiving KADCYLA, apprise the patient of the potential hazard to the fetus. Patients should be advised to use effective contraception during treatment with KADCYLA and for 6 months following the last dose of KADCYLA.
If KADCYLA is administered during pregnancy or if a patient becomes pregnant while receiving KADCYLA, immediately report exposure to the Genentech Adverse Event Line at 1-888-835-2555. Encourage women who may be exposed during pregnancy to enroll in the MotHER Pregnancy Registry by contacting 1-800-690-6720 [see Patient Counseling Information (17)].
Human Data
In the post-marketing setting, treatment with trastuzumab during pregnancy has resulted in cases of oligohydramnios, some associated with fatal pulmonary hypoplasia, skeletal abnormalities and neonatal death. These case reports described oligohydramnios in pregnant women who received trastuzumab either alone or in combination with chemotherapy. In some case reports, amniotic fluid index increased after trastuzumab was stopped. In one case, trastuzumab therapy resumed after the amniotic fluid index improved, and oligohydramnios recurred.
Animal Data
There were no reproductive and developmental toxicology studies conducted with ado-trastuzumab emtansine. DM1, the cytotoxic component of KADCYLA, disrupts microtubule function. DM1 is toxic to rapidly dividing cells in animals and is genotoxic, suggesting it has the potential to cause embryotoxicity and teratogenicity. In studies where trastuzumab was administered to pregnant monkeys at doses up to 25 mg/kg (about 7 times the clinical dose), trastuzumab crossed the placental barrier during the early and late phases of gestation. The resulting concentrations of trastuzumab in fetal blood and amniotic fluid were approximately 33% and 25%, respectively, of those present in the maternal serum but were not associated with adverse findings.
8.3 Nursing Mothers
It is not known whether KADCYLA, specifically, is excreted in human milk, but IgG is known to be excreted in human milk. In lactating monkeys, trastuzumab was excreted in small amounts (about 0.3% of materna
