Patients treated w/ Kadcyla must have confirmed HER2-positive tumor status as assessed by either HER2 protein over-expression or gene amplification. Increased risk of pulmonary events in patients w/ dyspnea. Permanently discontinue use in patients diagnosed w/ interstitial lung disease, or pneumonitis, patients w/ serum transaminases >3 x ULN & concomitant total bilirubin >2 x ULN, in cases of nodular regenerative hyperplasia. Monitor liver function prior to initiation of therapy & each Kadcyla dose. Increased risk of developing left ventricular dysfunction. Perform standard cardiac function testing prior to initiation & at regular intervals (eg, every 3 mth) during treatment. Patients w/ LVEF <50% prior to initial therapy. Interrupt treatment in patients w/ severe infusion-related reactions & permanently discontinue in life-threatening infusion-related reaction. Hypersensitivity reactions eg, serious anaphylactic reactions. Cases of hemorrhagic events. Closely monitor patients w/ thrombocytopenia & on anticoagulant treatment. Monitor platelet counts prior to each dose. Do not administer in decreased platelet count to ≥Grade 3 (<50,000/mm3
). Neurotoxicity. Temporarily discontinue in patients experiencing Grade 3 or 4 peripheral neuropathy until resolved or improved to ≤Grade 2. Closely monitor infusion site for possible subcutaneous infiltration during drug administration. Patients experiencing symptoms of infusion related reactions should be advised not to drive & use machines until symptoms abate. Women of childbearing potential should use effective contraception during & at least 7 mth after treatment. Discontinue lactation prior to initial treatment & may begin 7 mth after concluding treatment. Hepatic impairment. Pregnancy. Childn <18 yr.