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What is Kadcyla® ? (ado-trastuzumab emtansine)

Kadcyla is a targeted treatment for metastatic breast cancers that are positive for human epidermal growth factor receptor 2 (HER2+) that have already been previously treated with Herceptin® (trastuzumab) and a type of chemotherapy known as a taxane, either individually or in combination. Kadcyla is also approved in early breast cancer for use as an adjuvant (after surgery) treatment for HER2-positive early breast cancer when the patient has taken neoadjuvant (before surgery) treatment including a taxane and trastuzumab (Herceptin®) and there is cancer remaining in the tissue removed during surgery. Kadcyla is manufactured by Genentech.1,2

What is the ingredient in Kadcyla?

The active ingredient in Kadcyla is ado-trastuzumab emtansine, a combination of two medications that can attack breast cancer: a monoclonal antibody (trastuzumab) and a chemotherapy.1,2

How does Kadcyla work?

Kadcyla is a combination of a monoclonal antibody and a chemotherapy medication. Like antibodies that are created by the body to target specific invaders, monoclonal antibodies are created in a laboratory to attach to specific proteins. Kadcyla targets the HER2 receptor. Breast cancers that have an excess of HER2 receptors can grow and spread quickly. Blocking the HER2 receptor can slow or block the growth of these cancers. In addition, by selectively attaching to the HER2 receptor, Kadcyla can deliver its chemotherapy ingredient directly to cancer cells which have the receptor, causing the cancer cell to die.3

What are some of the possible side effects of Kadcyla

Kadcyla may cause serious side effects, including1,2:

  • Liver failure, which may lead to death
  • Heart problems, such as congestive heart failure or reduced heart function
  • Serious harm to an unborn baby, which may cause serious birth defects or death
  • Lung problems, which could be life-threatening
  • Infusion-related reactions
  • Nerve damage

Liver problems may cause symptoms such as vomiting, nausea, lack of appetite, yellowing of the skin or eyes (jaundice), stomach pain, dark-colored urine, or itching.1,2

Heart problems may cause symptoms such as shortness of breath, swelling of the ankles or legs, cough, rapid weight gain (potentially more than 5 pounds in less than 24 hours), dizziness, loss of consciousness, or irregular heartbeat.1,2

Lung problems may cause symptoms such as difficulty breathing, coughing, tiredness, and fluid in the lungs.1,2

Infusion-related reactions may cause symptoms such as flushing (redness or heat to the skin), fever, chills, difficulty breathing, wheezing, low blood pressure, or a fast heartbeat.1,2

Nerve damage may cause symptoms such as numbness, tingling, pain, sensitivity to touch, muscle weakness, or a lack of coordination.1,2
The most common side effects experienced by patients taking Kadcyla in clinical trials included1,2:

  • Fatigue
  • Nausea
  • Muscle and bone pain
  • Lowered platelet counts (which can increase risk of bleeding)
  • Headache
  • Liver problems
  • Constipation
  • Nosebleeds

Things to know about Kadcyla

Because Kadcyla can cause birth defects or fatal harm to an unborn fetus, women who can become pregnant who receive Kadcyla should use birth control during their treatment and for 7 months after treatment is completed.1,2

During treatment with Kadcyla, patients will be monitored for signs of a potential infusion-related reaction.1

Because Kadcyla can lower the number of platelets in the blood and increase the risk of bleeding, patients should have additional monitoring if they take treatments to prevent blood clots, such as anticoagulants, antiplatelet medications, or blood thinners. Life-threatening bleeding can occur with Kadcyla.1,2

Women should not breastfeed while receiving Kadcyla and for 7 months after treatment is completed, as the medication can be harmful to a breastfeeding infant.

Dosing information

Kadcyla is given as an intravenous (IV) infusion and is generally given every 3 weeks. Treatment may be discontinued if the cancer progresses or if side effects become intolerable. In some cases, treatment may be temporarily paused, or the dose may be lessened to manage side effects.1

For more information, read the full prescribing information of Kadcyla.

Patients should talk to their doctor if they have any questions, or if they have questions regarding their ado-trastuzumab emtansine regimen.

Written by: Editorial Team | Last reviewed: October 2019.
  1. Kadcyla prescribing information. Genentech USA, Inc. Available at Accessed 9/17/18.
  2. Kadcyla product website. Available at Accessed 9/17/18.
  3. Kadcyla. Chemocare. Available at Accessed 9/17/18.