Kadcyla Drug Information

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.

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.

Patient Selection

Select patients based on HER2 protein overexpression or HER2 gene amplification in tumor specimens. 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.

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. 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.

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.

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.

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 Table 2 Dose Modification Guidelines for KADCYLA

Preparation for Administration

In order to prevent medication errors it is important to check the vial labels to ensure that the drug being prepared and administered is KADCYLA (ado-trastuzumab emtansine) and not trastuzumab. Administration: Administer KADCYLA as an intravenous infusion only with a 0.2 or 0.22 micron in-line polyethersulfone (PES) filter. Do not administer as an intravenous push or bolus.

Do not mix KADCYLA, or administer as an infusion, with other medicinal products. Reconstitution: Use aseptic technique for reconstitution and preparation of dosing solution. Appropriate procedures for the preparation of chemotherapeutic drugs should be used.

Swirl the vial gently until completely dissolved. Do not shake. Inspect the reconstituted solution for particulates and discoloration.

The reconstituted solution should be clear to slightly opalescent and free of visible particulates. The color of the reconstituted solution should be colorless to pale brown. Do not use if the reconstituted solution contains visible particulates or is cloudy or discolored.

The reconstituted lyophilized vials should be used immediately following reconstitution with Sterile Water for Injection or 0.45% Sodium Chloride Injection. If not used immediately, the reconstituted KADCYLA vials can be stored for up to 120 hours (5 days) in a refrigerator at 2°C to 8°C (36°F to 46°F); discard unused KADCYLA after 120 hours (5 days) if stored at 2°C to 8°C (36°F to 46°F). Do not freeze.

The reconstituted product contains no preservative and is intended for single-dose only. Dilution: Determine the correct dose (mg) of KADCYLA. Calculate the volume of the 20 mg/mL reconstituted KADCYLA solution needed.

Withdraw this amount from the vial and add it to an infusion bag containing 250 mL of 0.9% Sodium Chloride Injection. Do not use Dextrose (5%) solution. Gently invert the bag to mix the solution in order to avoid foaming.

The diluted KADCYLA infusion solution should be used immediately. If not used immediately, the solution may be stored in a refrigerator at 2°C to 8°C (36°F to 46°F) for up to 24 hours prior to use. This storage time is additional to the time allowed for the reconstituted vials.

Do not freeze or shake.

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. 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.

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 NCI–CTCAE (version 3) Grade ≥ 3 adverse reactions (frequency > 2%) were thrombocytopenia, increased transaminases, anemia, hypokalemia, peripheral neuropathy and fatigue. Table 3 Adverse Reactions Occurring in ≥ 10% of Patients on the KADCYLA Treatment Arm in the EMILIA Trial Grouped terms were used for the following Adverse Reactions: Thrombocytopenia: thrombocytopenia, platelet count decreased Anemia: anemia, hemoglobin decreased Abdominal pain: abdominal pain, abdominal pain upper Stomatitis: stomatitis, mucosal inflammation, oropharyngeal pain Transaminases Increased: transaminases increased, aspartate aminotransferase increased, alanine aminotransferase increased, gamma-glutamyltransferase increased, liver function test abnormal, hepatic enzyme increased, hepatic function abnormal Hypokalemia: hypokalemia, blood potassium decreased Musculoskeletal Pain: muscle spasms, musculoskeletal discomfort, musculoskeletal chest pain, back pain, pain in extremity, bone pain, musculoskeletal pain Peripheral neuropathy: neuropathy peripheral, peripheral sensory neuropathy, peripheral motor neuropathy, paresthesia Hemorrhage: Hemorrhage terms (excl laboratory terms) (SMQ, wide), The following clinically relevant adverse reactions were reported in < 10% of patients in the KADCYLA-treated group in EMILIA: dyspepsia (9%), urinary tract infection (9%), chills (8%), dysgeusia (8%), neutropenia (7%), peripheral edema (7%), pruritus (6%), hypertension (5%), blood alkaline phosphatase increased (4.7%), vision blurred (4.5%), conjunctivitis (3.9%), dry eye (3.9%), lacrimation increased (3.3%), drug hypersensitivity (2.2%), left ventricular dysfunction (1.8%), infusion-related reaction (1.4%), pneumonitis (1.2%), nodular regenerative hyperplasia (0.4%), portal hypertension (0.4%).

The adverse reactions described in Table 5 were identified in patients with HER2-positive early breast cancer treated in the KATHERINE trial. Patients were randomized to receive KADCYLA or trastuzumab. The median duration of study treatment was 10 months for patients in the KADCYLA-treated group and 10 months for patients treated with trastuzumab.

One hundred and thirty-three patients (18%) discontinued KADCYLA due to an adverse reaction, compared with 15 patients (2.1%) who discontinued trastuzumab due to an adverse reaction. The most common adverse reactions leading to KADCYLA discontinuation (in ≥ 1% of patients) were platelet count decreased, blood bilirubin increased, ejection fraction decreased, AST increased, ALT increased, and peripheral neuropathy. One hundred and six patients (14%) treated with KADCYLA had dose reductions.

Adverse reactions that led to dose delays occurred in 106 (14%) of KADCYLA treated patients. Selected laboratory abnormalities are shown in Table 6. The most common adverse reactions seen with KADCYLA in the randomized trial (frequency > 25%) were fatigue, nausea, increased transaminases, musculoskeletal pain, hemorrhage, thrombocytopenia, headache, peripheral neuropathy, and arthralgia.

Table 6 Selected Laboratory Abnormalities (KATHERINE)

Post-Marketing Experience

The following adverse reactions have been identified during post-approval use of KADCYLA. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Adverse Reactions from Observational Studies CHF and > 10% reduction in LVEF in patients with HER2-positive metastatic breast cancer with a baseline LVEF of 40-49% treated with KADCYLA.

Adverse Reactions from Postmarketing Spontaneous Reports Tumor lysis syndrome (TLS) Skin/tissue necrosis after extravasation

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.

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. Based on its mechanism of action, the DM1 component of KADCYLA can also cause embryo-fetal harm when administered to a pregnant woman. 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. 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. 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.

Pediatric Use Safety and effectiveness of KADCYLA have not been established in pediatric patients.

There is no known antidote for overdose of KADCYLA. In clinical trials, overdose of KADCYLA has been reported at approximately two times the recommended dose which resulted in Grade 2 thrombocytopenia (resolved 4 days later) and one death. In the fatal case, the patient incorrectly received KADCYLA at 6 mg/kg and died approximately 3 weeks following the overdose; a cause of death and a causal relationship to KADCYLA were not established.