KADCYLA

1 INDICATIONS AND USAGE KADCYLA is a HER2-targeted antibody and microtubule inhibitor conjugate indicated, as a single agent, for: the treatment of patients with HER2-positive, metastatic breast cancer who previously received trastuzumab and a taxane, separately or in combination. Patients should have either: received prior therapy for metastatic disease, or developed disease recurrence during or within six months of completing adjuvant therapy. ( 1.1 ) the adjuvant treatment of patients with HER2-positive early breast cancer who have residual invasive disease after neoadjuvant taxane and trastuzumab-based treatment. ( 1.2 ) Select patients for therapy based on an FDA-authorized test for KADCYLA [see Dosage and Administration (2.1) ] 1.1 Metastatic Breast Cancer (MBC) KADCYLA ® , as a single agent, is indicated for the treatment of patients with HER2-positive, metastatic breast cancer who previously received trastuzumab and a taxane, separately or in combination. Patients should have either: Received prior therapy for metastatic disease, or Developed disease recurrence during or within six months of completing adjuvant therapy. Select patients for therapy based on an FDA-authorized test for KADCYLA [ see Dosage and Administration (2.1) ]. 1.2 Early Breast Cancer (EBC) KADCYLA, as a single agent, is indicated for the adjuvant treatment of patients with HER2-positive early breast cancer who have residual invasive disease after neoadjuvant taxane and trastuzumab -based treatment. Select patients for therapy based on an FDA-authorized test for KADCYLA [ see Dosage and Administration (2.1) ].

2 DOSAGE AND ADMINISTRATION Do not substitute KADCYLA for or with trastuzumab. HER2 Testing: Perform using FDA-authorized tests by laboratories with demonstrated proficiency. ( 2.1 ) For intravenous infusion only . Do not administer as an intravenous push or bolus. Do not use Dextrose (5%) solution. ( 2.4 ) The recommended dose of KADCYLA is 3.6 mg/kg given as an intravenous infusion every 3 weeks (21-day cycle) until disease progression or unacceptable toxicity, or a total of 14 cycles for patients with EBC. Do not administer KADCYLA at doses greater than 3.6 mg/kg. ( 2.2 ) Management of adverse reactions (infusion-related reactions, hepatotoxicity, left ventricular cardiac dysfunction, thrombocytopenia, pulmonary toxicity or peripheral neuropathy) may require temporary interruption, dose reduction, or treatment discontinuation of KADCYLA. ( 2.3 ) 2.1 Patient Selection Select patients based on HER2 protein overexpression or HER2 gene amplification in tumor specimens [see Indications and Usage (1) , Clinical Studies (14) ]. Assessment of HER2 protein overexpression and/or HER2 gene amplification should be performed using FDA-authorized tests specific for breast cancers by laboratories with demonstrated proficiency. Information on the FDA-authorized tests for the detection of HER2 protein overexpression and HER2 gene amplification is available at: http://www.fda.gov/CompanionDiagnostics. Improper assay performance, including use of sub-optimally fixed tissue, failure to utilize specified reagents, deviation from specific assay instructions, and failure to include appropriate controls for assay validation, can lead to unreliable results. 2.2 Recommended Doses and Schedules Do not substitute trastuzumab for or with KADCYLA. The recommended dose of KADCYLA is 3.6 mg/kg given as an intravenous infusion every 3 weeks (21-day cycle). Do not administer KADCYLA at doses greater than 3.6 mg/kg . Closely monitor the infusion site for possible subcutaneous infiltration during drug administration [see Warnings and Precautions (5.9) ] . First infusion: Administer infusion over 90 minutes. Observe patients during the infusion and for at least 90 minutes following the initial dose for fever, chills, or other infusion-related reactions [see Warnings and Precautions (5.5) ] . Subsequent infusions: Administer over 30 minutes if prior infusions were well tolerated. Observe patients during the infusion and for at least 30 minutes after infusion. Metastatic Breast Cancer (MBC) Patients with MBC should receive treatment until disease progression or unmanageable toxicity. Early Breast Cancer (EBC) Patients with EBC should receive treatment for a total of 14 cycles unless there is disease recurrence or unmanageable toxicity. 2.3 Dose Modifications Do not re-escalate the KADCYLA dose after a dose reduction is made. If a planned dose is delayed or missed, administer as soon as possible; do not wait until the next planned cycle. Adjust the schedule of administration to maintain a 3-week interval between doses. Administer the infusion at the dose and rate the patient tolerated in the most recent infusion. Slow or interrupt the infusion rate of KADCYLA if the patient develops an infusion-related reaction. Permanently discontinue KADCYLA for life-threatening infusion-related reactions [see Warnings and Precautions (5.5) ] . Management of increased serum transaminases, hyperbilirubinemia, left ventricular dysfunction, thrombocytopenia, pulmonary toxicity or peripheral neuropathy may require temporary interruption, dose reduction or treatment discontinuation of KADCYLA as per guidelines provided in Tables 1 and 2 . Table 1 Recommended Dose Reduction Schedule for Adverse Reactions Dose Reduction Schedule Dose Level Starting dose 3.6 mg/kg First dose reduction 3 mg/kg Second dose reduction 2.4 mg/kg Requirement for further dose reduction Discontinue treatment Table 2 Dose Modification Guidelines for KADCYLA ALT = alanine transaminase; AST = aspartate transamina…

5 WARNINGS AND PRECAUTIONS Pulmonary Toxicity: Permanently discontinue KADCYLA in patients diagnosed with interstitial lung disease or pneumonitis. For patients with radiation pneumonitis in the adjuvant setting, permanently discontinue KADCYLA for Grade ≥ 3 or for Grade 2 not responding to standard treatment. ( 2.2 , 5.4 ) Infusion-Related Reactions, Hypersensitivity Reactions: Monitor for signs and symptoms during and after infusion. If significant infusion-related reactions or hypersensitivity reactions occur, slow or interrupt the infusion and administer appropriate medical therapies. Permanently discontinue KADCYLA for life threatening infusion-related reaction. ( 2.1 , 2.2 , 5.5 ) Hemorrhage: Fatal cases of hemorrhage occurred in clinical trials among patients with no known identified risk factors, as well as among patients with thrombocytopenia and those receiving anti-coagulation and antiplatelet therapy. Use caution with these agents and consider additional monitoring when concomitant use is medically necessary . ( 5.6 ) Thrombocytopenia: Monitor platelet counts prior to each KADCYLA dose. Institute dose modifications as appropriate. ( 2.2 , 5.7 ) Neurotoxicity: Monitor for signs or symptoms. Withhold dosing temporarily for patients experiencing Grade 3 or 4 peripheral neuropathy. ( 2.2 , 5.8 , 13.2 ) 5.1 Hepatotoxicity Hepatotoxicity, predominantly in the form of asymptomatic, transient increases in the concentrations of serum transaminases, has been observed in clinical trials with KADCYLA [see Adverse Reactions (6.1) ] . Serious hepatotoxicity, including 3 fatal cases, has been observed in clinical trials (n=1624) with KADCYLA as single-agent. All fatal cases occurred in MBC clinical trials with KADCYLA, which included severe drug-induced liver injury and associated hepatic encephalopathy. Some of the patients experiencing hepatotoxicity had comorbidities and/or concomitant medications with known hepatotoxic potential. Monitor serum transaminases and bilirubin prior to initiation of KADCYLA treatment and prior to each KADCYLA dose. Patients with known active liver disease (such as, hepatitis B virus or hepatitis C virus) were excluded from the EMILIA and KATHERINE studies [see Clinical Studies (14.1) ] . Reduce the dose or discontinue KADCYLA as appropriate in cases of increased serum transaminases and/or total bilirubin [see Dosage and Administration (2.2) ] . Permanently discontinue KADCYLA treatment in patients with serum transaminases > 3 × ULN and concomitant total bilirubin > 2 × ULN. KADCYLA has not been studied in patients with serum transaminases > 2.5 × ULN or bilirubin > 1.5 × ULN prior to the initiation of treatment. In clinical trials of KADCYLA, cases of nodular regenerative hyperplasia (NRH) of the liver have been identified from liver biopsies (5 cases out of 1624 treated patients, one of which was fatal). Two of these five cases of NRH were observed in EMILIA and two were observed in KATHERINE [see Adverse Reactions (6.1) ] . NRH is a rare liver condition characterized by widespread benign transformation of hepatic parenchyma into small regenerative nodules; NRH may lead to non-cirrhotic portal hypertension. The diagnosis of NRH can be confirmed only by histopathology. NRH should be considered in all patients with clinical symptoms of portal hypertension and/or cirrhosis-like pattern seen on the computed tomography (CT) scan of the liver but with normal transaminases and no other manifestations of cirrhosis. Upon diagnosis of NRH, KADCYLA treatment must be permanently discontinued. 5.2 Left Ventricular Dysfunction Patients treated with KADCYLA are at increased risk of developing left ventricular dysfunction. A decrease of LVEF to < 40% has been observed in patients treated with KADCYLA. Serious cases of heart failure, with no fatal cases, have been observed in clinical trials with KADCYLA. In EMILIA, left ventricular dysfunction occurred in 1.8% of patients in the KADCYLA-treated group and 3.3% of …

4 CONTRAINDICATIONS None. None. ( 4 )

7 DRUG INTERACTIONS No formal drug-drug interaction studies with KADCYLA have been conducted. In vitro studies indicate that DM1, the cytotoxic component of KADCYLA, is metabolized mainly by CYP3A4 and to a lesser extent by CYP3A5. Concomitant use of strong CYP3A4 inhibitors (e.g., ketoconazole, 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.

8.1 Pregnancy If KADCYLA is administered during pregnancy, or if a patient becomes pregnant while receiving KADCYLA or within 7 months following the last dose of KADCYLA, health care providers and patients should immediately report KADCYLA exposure to Genentech at 1-888-835-2555. Risk Summary KADCYLA can cause fetal harm when administered to a pregnant woman. There are no available data on the use of KADCYLA in pregnant women. Cases of oligohydramnios and oligohydramnios sequence manifesting as pulmonary hypoplasia, skeletal abnormalities, and neonatal death were observed in the postmarketing setting in patients treated with trastuzumab, the antibody component of KADCYLA [see Data ] . Based on its mechanism of action, the DM1 component of KADCYLA can also cause embryo-fetal harm when administered to a pregnant woman [ see Data ]. Apprise the patient of the potential risks to a fetus. There are clinical considerations if KADCYLA is used in a pregnant woman, or if a patient becomes pregnant within 7 months following the last dose of KADCYLA [see Clinical Considerations ]. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Clinical Considerations Fetal/Neonatal Adverse Reactions Monitor women who received KADCYLA during pregnancy or within 7 months prior to conception for oligohydramnios. If oligohydramnios occurs, perform fetal testing that is appropriate for gestational age and consistent with community standards of care. Data Human Data There are no available data on the use of KADCYLA in pregnant women. In the post-marketing setting, cases of oligohydramnios, and of oligohydramnios sequence, manifesting in the fetus as pulmonary hypoplasia, skeletal abnormalities and neonatal death were observed after treatment with trastuzumab during pregnancy. 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 amniotic 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 cynomolgus monkeys during the period of organogenesis at doses up to 25 mg/kg given twice weekly (about 7 times the clinical dose), trastuzumab crossed the placental barrier during the early (Gestation Days 20 to 50) and late (Gestation Days 120 to 150) phases of gestation. The resulting concentrations of trastuzumab in fetal serum and amniotic fluid were approximately 33% and 25%, respectively, of those present in the maternal serum but were not associated with adverse developmental effects.

6 ADVERSE REACTIONS The following adverse reactions are discussed in greater detail in other sections of the label: Hepatotoxicity [See Warnings and Precautions (5.1) ] Left Ventricular Dysfunction [See Warnings and Precautions (5.2) ] Embryo-Fetal Toxicity [See Warnings and Precautions (5.3) ] Pulmonary Toxicity [See Warnings and Precautions (5.4) ] Infusion-Related Reactions, Hypersensitivity Reactions [See Warnings and Precautions (5.5) ] Hemorrhage [See Warnings and Precautions (5.6) ] Thrombocytopenia [See Warnings and Precautions (5.7) ] Neurotoxicity [See Warnings and Precautions (5.8) ] Metastatic Breast Cancer The most common adverse reactions (≥ 25%) with KADCYLA were fatigue, nausea, musculoskeletal pain, hemorrhage, thrombocytopenia, headache, increased transaminases, constipation and epistaxis. ( 6.1 ) Early Breast Cancer The most common adverse reactions (≥ 25%) with KADCYLA were fatigue, nausea, increased transaminases, musculoskeletal pain, hemorrhage, thrombocytopenia, headache, peripheral neuropathy, and arthralgia. To report SUSPECTED ADVERSE REACTIONS, contact Genentech at 1-888-835-2555 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The data in the WARNINGS AND PRECAUTIONS reflect exposure to KADCYLA as a single agent at 3.6 mg/kg given as an intravenous infusion every 3 weeks (21-day cycle) in 1624 patients including 884 patients with HER2-positive metastatic breast cancer and 740 patients with HER2-positive early breast cancer (KATHERINE trial). Metastatic Breast Cancer In clinical trials, KADCYLA has been evaluated as single-agent in 884 patients with HER2-positive metastatic breast cancer. The most common (≥ 25%) adverse reactions were fatigue, nausea, musculoskeletal pain, hemorrhage, thrombocytopenia, headache, increased transaminases, constipation and epistaxis. The adverse reactions described in Table 3 were identified in patients with HER2-positive metastatic breast cancer treated in the EMILIA trial [see Clinical Studies (14.1) ] . Patients were randomized to receive KADCYLA or lapatinib plus capecitabine. The median duration of study treatment was 7.6 months for patients in the KADCYLA-treated group and 5.5 months and 5.3 months for patients treated with lapatinib and capecitabine, respectively. In the EMILIA trial, 43% of patients experienced Grade ≥ 3 adverse reactions in the KADCYLA-treated group compared with 59% of patients in the lapatinib plus capecitabine-treated group. Dose adjustments for KADCYLA were permitted [see Dosage and Administration (2.2) ] . Thirty-two patients (7%) discontinued KADCYLA due to an adverse reaction, compared with 41 patients (8%) who discontinued lapatinib, and 51 patients (10%) who discontinued capecitabine due to an adverse reaction. The most common adverse reactions leading to KADCYLA discontinuation were thrombocytopenia and increased transaminases. Eighty patients (16%) treated with KADCYLA had adverse reactions leading to dose reductions. The most frequent adverse reactions leading to dose reduction of KADCYLA (in ≥ 1% of patients) included thrombocytopenia, increased transaminases, and peripheral neuropathy. Adverse reactions that led to dose delays occurred in 116 (24%) of KADCYLA treated patients. The most frequent adverse reactions leading to a dose delay of KADCYLA (in ≥ 1% of patients) were neutropenia, thrombocytopenia, leukopenia, fatigue, increased transaminases and pyrexia. Table 3 reports the adverse reactions that occurred in patients in the KADCYLA-treated group (n=490) of the EMILIA trial. Selected laboratory abnormalities are shown in Table 4 . The most common adverse reactions seen with KADCYLA in the randomized trial (frequency > 25%) were nausea…