Ado-trastuzumab emtansine is used to treat a HER2-positive breast cancer. ado-trastuzumab emtansine is used both for early breast cancer and for breast cancer that has spread to other parts of the body (metastatic).

Ado-trastuzumab emtansine is usually given after other treatments have failed.

Kadcyla (ado-trastuzumab) should not be used in place of Herceptin (trastuzumab).

Ado-trastuzumab emtansine may also be used for purposes not listed in this medication guide.

Do not use if you are pregnant. Use effective birth control, and tell your doctor if you become pregnant during treatment.

ado-trastuzumab emtansine can cause serious side effects on your liver or heart. Call your doctor at once if you have upper stomach pain, loss of appetite, dark urine, yellowing of your skin or eyes, shortness of breath, cough, swelling, rapid weight gain, fast or pounding heartbeats, dizziness, or if you feel like you might pass out.

Ado-trastuzumab emtansine is given as an infusion into a vein. A healthcare provider will give you this injection.

ado-trastuzumab emtansine must be given slowly, and the infusion can take 30 to 90 minutes to complete.

Tell your caregivers if you feel any burning, pain, or swelling around the IV needle when ado-trastuzumab emtansine is injected.

Ado-trastuzumab emtansine is usually given once every 3 weeks. Your doctor will determine how long to treat you.

You may need frequent medical tests to be sure this medicine is not causing harmful effects. Your cancer treatments may be delayed based on the results.

Usual Adult Dose for Breast Cancer:

3.6 mg/kg IV every 3 weeks (21-day cycle) until disease progression or unacceptable toxicity
Maximum dose: 3.6 mg/kg IV every 3 weeks

Comments:
-Administer the first infusion over 90 minutes. Subsequent infusions may be administered over 30 minutes as tolerated.
-Observe patients during and for at least 90 minutes following the initial dose for fever, chills, or other infusion-related reactions.
-Patients should have a HER2 positive tumor status confirmed prior to starting therapy.
-Do not substitute trastuzumab emtansine for or with trastuzumab.
-If a planned dose is delayed or missed, it should be administered as soon as possible; do not wait until the next planned cycle.

Use: As a single agent, for HER2-positive, metastatic breast cancer in patients 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 6 months of completing adjuvant therapy

Tell your doctor if you have ever had:

• heart problems;

• liver disease (especially hepatitis B or C);

• bleeding or blood clotting disorder such as hemophilia; or

• asthma, chronic obstructive pulmonary disease (COPD), sleep apnea, or other breathing disorder.

You may need to have a negative pregnancy test before starting this treatment.

Ado-trastuzumab emtansine can harm an unborn baby if the mother or the father is using this medicine.

• If you are a woman, do not use ado-trastuzumab emtansine if you are pregnant. Use effective birth control to prevent pregnancy while you are using this medicine and for at least 7 months after your last dose.

• If you are a man, use effective birth control if your sex partner is able to get pregnant. Keep using birth control for at least 4 months after your last dose.

• Tell your doctor right away if a pregnancy occurs while either the mother or the father is using ado-trastuzumab emtansine.

Do not breastfeed while using this medicine, and for at least 7 months after your last dose.

Call your doctor for instructions if you miss an appointment for your ado-trastuzumab emtansine injection.

Since this medication is given by a healthcare professional in a medical setting, an overdose is unlikely to occur.

Avoid activities that may increase your risk of bleeding or injury. Use extra care to prevent bleeding while shaving or brushing your teeth.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Some side effects may occur during the injection. Tell your caregiver right away if you feel cold, light-headed, feverish or sweaty, or have chest tightness, rapid heartbeats, or trouble breathing.

Ado-trastuzumab emtansine may cause serious side effects. Call your doctor at once if you have:

• easy bruising, unusual bleeding, purple or red spots under your skin;

• coughing up blood or vomit that looks like coffee grounds;

• bloody or tarry stools;

• chest pain, wheezing, dry cough;

• unusual tiredness, feeling light-headed;

• pale skin, cold hands and feet;

• numbness, tingling, or burning pain in your hands or feet;

• sudden numbness or weakness (especially on one side of the body), severe headache, slurred speech, balance problems;

• heart problems--swelling in your lower legs, rapid weight gain, feeling short of breath, cough, fast or pounding heartbeat, dizziness, feeling like you might pass out;

• liver problems--loss of appetite, stomach pain (upper right side), dark urine, jaundice (yellowing of the skin or eyes); or

• signs of tumor cell breakdown--confusion, weakness, muscle cramps, nausea, vomiting, fast or slow heart rate, decreased urination, tingling in your hands and feet or around your mouth.

Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.

Common side effects of ado-trastuzumab emtansine may include:

• easy bruising or bleeding (especially nosebleeds);

• nausea, constipation;

• joint or muscle pain;

• headache; or

• feeling tired.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Other drugs may affect ado-trastuzumab emtansine, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.