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Treatment Name: Ado-trastuzumab emtansine (Kadcyla®)

Ado-trastuzumab emtansine (Kadcyla®) is a Chemotherapy Regimen for Breast Cancer - metastatic

How does ado-trastuzumab emtansine work?
It targets a protein on the surface of breast cancer cells known as human epidermal growth factor receptor 2 (HER-2). Once it is bound to the protein, it then enters the cells and releases a chemical called DM-1 which stops the cell from growing or dividing.

Goals of therapy:
Ado-trastuzumab emtansine is given to shrink breast cancer tumors and slow the disease, which can decrease symptoms and extend life. It is not commonly given with the goal of cure.


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  • Ado-trastuzumab emtansine intravenous infusion (I.V.) over 90 minutes on Day 1 of Cycle 1, then over 30 minutes on Day 1 of all following cycles

Estimated total infusion time for this treatment:

  • Up to 3 hours for Cycle 1, Day 1; as short as 1.5 hours for the next cycles if well tolerated. If there are any infusion-related reactions, the infusion may need to be stopped
  • The observation time may last 30 to 90 minutes after the infusion to monitor for any infusion-related reactions
  • Infusion times are based on clinical studies, but may vary depending on doctor preference or patient tolerability. Pre-medications and I.V. fluids, such as hydration, may add more time

Ado-trastuzumab emtansine is usually given in an outpatient infusion center, allowing the person to go home afterwards. This treatment is repeated every 21 days, which is known as one Cycle. Each cycle is repeated until the drug no longer works or until unacceptable side effects occur.

Click here for common starting doses.

Side Effects

In clinical studies, the most commonly reported side effects with ado-trastuzumab emtansine are shown here:

A note about side effect percentages

  • Nausea (39%)
  • Fatigue (35%)
  • Increased bleeding risk [low platelets; thrombocytopenia] (28%)
  • Diarrhea (23%)
  • Vomiting (19%)
  • Anemia [low red blood cells] (10%)
  • Low blood potassium (9%)
  • Mouth sores (7%)
  • Low white blood cells [neutropenia] (6%)
  • Skin redness and peeling on palms of hands and soles of feet (1%) 

On average, 6% of patients discontinue treatment with ado-trastuzumab due to unacceptable side effects.

Importantly, not all people who experience a side effect from Ado-trastuzumab emtansine (Kadcyla®) will experience it in the same way. It may be mild in some or severe in others, depending upon the individual. Everybody is different. Additionally, side effects may vary over time. For some, side effects may be a reason to delay or switch treatment, reduce the dose, or avoid future treatment with a certain medication altogether.

Side effects may be treatable when they occur or preventable by taking certain medications before they happen. When medications are taken to prevent a problem, this is known as prophylaxis, or "prophy" for short.

After starting treatment with (Kadcyla®), be sure to come back and watch all of the side effect videos shown below. Each of these videos contain valuable information about side effect management that will hopefully help you to both feel better and stay out of the hospital.

Side effect videos Side Effect Videos
Nausea and VomitingNausea and VomitingFatigue Fatigue BleedingBleedingDiarrheaDiarrheaAnemiaAnemia


How often is monitoring needed?
Labs (blood tests) may be checked before each treatment. Labs often include: Complete Blood Count (CBC), and Comprehensive Metabolic Panel (CMP). Heart function is checked for ejection fraction before and during treatment.

How often is imaging needed?
Imaging may be checked before treatment and every two to four cycles during treatment. Imaging may include: bone scans and computerized tomography (CT) scans.

How might blood test results/imaging affect treatment?
Depending upon the results, your doctor may advise to continue ado-trastuzumab emtansine as planned, or delay or switch therapy.

ChemoExperts Tips

  • The risk of experiencing low platelets from ado-trastuzumab emtansine may be higher in patients with Asian ancestry
  • Your heart function will be checked before starting treatment and repeated every 3 months while receiving treatment with ado-trastuzumab emtansine. This is done by either an echocardiogram or a MUGA scan. Signs of decreased heart function include shortness of breath, dizziness, and swelling in ankles and feet
  • A pharmacist should ALWAYS review your medication list to ensure that drug interactions are prevented or managed appropriately
  • Clinical trials may exist for breast cancer. Ask your doctor if any studies are currently enrolling in your area. If not, go to to search for other centers offering study medications

Patient Assistance & Co-payment Coverage

Patients under the age of 65 years, or those with private insurance plans:
If you have insurance and are looking for patient assistance or copay assistance for Ado-trastuzumab emtansine (Kadcyla®), we have provided links that may help.

Visit our Patient Assistance page and click the links to various patient assistance programs for help paying for Ado-trastuzumab emtansine (Kadcyla®). Depending upon your income, they may be able to help cover the cost of:

  • Ado-trastuzumab emtansine

For Branded medications (may be available for generic medications too), check with the manufacturer to determine if a co-pay card is offered and if it could reduce your monthly copay.

  • If you are uninsured, check with the manufacturer to determine if you are eligible to receive medication at no cost.

Medicare and Medicaid patients (Patients 65 years or older):
The clinic providing treatment will likely pre-authorize medications and immune therapies such as Ado-trastuzumab emtansine (Kadcyla®) and are the best source to help you understand drug cost.

  • Ask to speak with a patient assistance technician or financial counselor at the clinic or hospital administering this therapy.

Emotional Wellness

What is Emotional Wellness?
Emotional wellness is having a positive outlook balanced with a realistic understanding of current life events. This requires both an awareness and acceptance of your emotions. It is with this knowledge that you can develop a plan to take the necessary actions to positively impact your life.

Emotional wellness uses an ongoing process to continually reflect on the stressors of life in a constructive manner to move forward and create happiness.

Because emotional wellness is deeply connected with physical, social, and spiritual wellness, pursuing it often becomes particularly difficult in times of major illness. Despite this difficulty, working toward emotional wellness has been connected to improved treatment outcomes and a higher likelihood of achieving goals of therapy.

Learn more about pursuing emotional wellness while receiving treatment with Ado-trastuzumab emtansine (Kadcyla®)

Individual Drug Label Information

Ado-trastuzumab emtansine (Kadcyla®)

  • Ado-trastuzumab is an intravenous infusion
  • Heart function, specifically the "ejection fraction," may decrease. Your heart function will be checked prior to treatment and typically every 3 months during treatment.
  • Liver damage may result. Your liver function will be checked before each dose to determine if the dose is appropriate
  • Do not use during pregnancy. Women of child bearing age should use effective contraception methods during therapy and for seven months after the end of therapy
  • If pregnancy occurs during treatment or within 7 months following the last dose of ado-trastuzumab emtansine, immediately call the Genentech Adverse Event Line at 1-888-835-2555. These women are encouraged to enroll in the MotHER Pregnancy Registry by contacting 1-800-690-6720
  • May interact with certain antifungal and seizure medications. Ask your doctor or pharmacist to review your medications for any possible interactions
General Ado-Trastuzumab (Kadcyla) Side Effects
  • Liver problems, increased LFT’s (liver function tests)
  • Heart problems, LVD (left ventricular dysfunction)
  • Although rare, serious lung toxicity can occur
  • Infusion reactions
  • Fatigue
  • Low platelets and related bleeding
  • Pins and needles or numbness in fingers and toes
  • Nausea and vomiting, but risk is low when anti-nausea medications are given before treatment
  • Skin rash
  • Constipation or diarrhea
  • Muscle or joint pain
  • Headache
  • Click on the ado-trastuzumab (Kadcyla) package insert below for reported side effects and possible drug interactions

Side Effect Videos
Nausea and VomitingNausea and VomitingDiarrheaDiarrheaFatigue Fatigue ConstipationConstipationPainPainAnemiaAnemia

See DailyMed package insert.

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Verma S, Miles D, Gianni L, et al. Trastuzumab Emtansine for HER2-Positive Advanced Breast Cancer. N Engl J Med 2012;367:1783-1791.

Created: December 20, 2015 Updated: January 8, 2020

What is Breast Cancer - metastatic?

What is Metastatic Breast Cancer?
A disease of the milk-producing glands known as lobules, milk ducts, or other cells found in the breast. Metastatic breast cancer is one that has moved from the breast to other areas of the body, which may include the brain, liver, or bone. Breast cancer is one of the most common types of cancers in women, but may rarely affect men as well. Known causes of breast cancer include genetic causes, such as the BRCA mutation, or obesity. The effectiveness of the treatment may depend upon the stage at diagnosis.

Types of metastatic breast cancer:
1. Hormone-receptor positive or negative (60 - 65% of patients)

  • Estrogen Receptor positive (ER)+ or negative (ER)-
  • Progestin Receptor positive (PR)+ or negative (PR)-

2. Hormone Epidermal growth factor Receptor-2 (HER-2) positive or negative (20 - 25% of patients)

  • HER-2 +
  • HER-2 -

3. Triple Negative (15 - 18% of patients)

  • ER- and PR- and (HER-2)-
NOTE: Treatment Options listed below are not all-inclusive. Other treatments may be available. ChemoExperts provides drug information and does not recommend any one treatment over another. Only your Doctor can choose which therapy is appropriate for you.

Common Starting Doses

Ado-trastuzumab emtansine 3.6 mg/kg IV over 90 minutes on Day 1 of Cycle 1, then over 30 minutes on Day 1 of all following cycles

Note: Individual doses may vary based upon your Doctor's recommendation, or drug availability

What is a CBC?

A Complete Blood Count (CBC) is a frequently ordered blood test that tells clinicians the status of your: 1) White blood cell count, 2) Hemoglobin, and 3) Platelet count at the time the test was taken.

Common uses:
1) White blood cell count (WBC): is used to determine infection risk, or response to chemotherapy. Certain chemotherapy agents may harm our good infection-fighting cells. Sometimes chemotherapy may need to be delayed to allow these cells to recover.

2) Hemoglobin: is used to determine if someone is anemic. Anytime the hemoglobin is below 12 g/dL, the person is said to be anemic. Red blood cell transfusions, and sometimes iron can be given to restore the hemoglobin level, but anemia treatment should always aim at treating the underlying cause or condition.

3) Platelet count: is used to determine if the risk of bleeding is increased or if a platelet transfusion is required to prevent bleeding. Certain medications that increase bleeding risk, such as: aspirin, certain chemotherapy agents, and blood thinners, may need to be stopped temporarily until the platelet count is within a safe range.

What is a CMP?

A Comprehensive Metabolic Panel (CMP) is a frequently ordered blood test that tells clinicians the status of your: 1) Electrolytes & Acid/Base status2) Kidney function, 3) Liver function, 4) Blood sugar, and 5) Calcium at the time the test was taken. It is commonly used to monitor liver and kidney function when beginning new medications such as chemotherapy. A total of 14 tests are run simultaneously and are shown below.

Electrolytes & Acid/Base status:
1) Sodium, 2) Potassium, 3) Carbon dioxide, 4) Chloride

Kidney Function:
5) BUN (blood urea nitrogen), 6) Serum creatinine (Scr)

Liver Function:
7) AST, 8) ALT, 9) Total bilirubin, 10) Alk Phos, 11) Albumin, 12) Total protein

Blood sugar:
13) Serum glucose

14) Serum calcium

What does Cure mean?

The word “cure” means there are no cancer cells left in the body and cancer will never come back. Depending on the cancer type and stage, this may be the true goal of therapy. However, it is very difficult to prove all cancer cells are gone. Even though images, like X-rays and MRI’s, and blood tests may not show any signs of cancer, there can be a small amount of cancer cells still left in the body. Because of this, the word “remission” is used more often. This means there are no signs or symptoms of cancer. Patients in remission are followed closely for any signs of cancer returning. Sometimes, more chemotherapy may be given while in remission to prevent the cancer from coming back.

Doctors usually do not consider a patient “cured” until the chance of cancer returning is extremely low. If cancer does return, it usually happens within 5 years of having a remission. Because of this, doctors do not consider a patient cured unless the cancer has not come back within 5 years of remission. The five-year cutoff does not apply to all cancers.

A note about side effect percentages

The number you see next to the percent sign (%) means how many people out of 100 are likely to experience this side effect.

For example, if the side effect is reported to occur in 8% of patients, this means that roughly 8 out of 100 people receiving this treatment will experience this side effect.