Kadcyla™ Approved for Breast Cancer

February 22, 2013 – The United States Food and Drug Administration (FDA) has approved Kadcyla (ado-trastuzumab emtansine) for the treatment of breast cancer. Kadcyla has been approved specifically for advanced, HER2-positive breast cancer that has progressed following therapy with Herceptin® and a taxane.

Breast cancer remains the second leading cause of cancer-related deaths in the United States among women. Approximately 15-20% of breast cancers are categorized as HER2-positive. This refers to a type of cancer that has more than normal quantities of a protein called the HER2 protein on the surface of the cancer cells.

The HER2 protein is part of a pathway that is involved in regular cellular growth. However, cancer cells that have increased quantities of the protein tend grow and spread at a greater rate than other cancer cells. Therefore, researchers have created agents designed specifically to target the HER2 protein in an attempt to slow the growth and spread of HER 2-positive cancer cells.

Herceptin®, Tykerb® and Perjeta™ are FDA-approved agents that are targeted against the HER2 protein. These agents bind specifically to the HER2-protein, slowing the cancer cells’ growth and stimulating an immune response against the cancer cells. Women diagnosed with breast cancer undergo testing to determine if they are HER2 positive prior to therapy.

Kadcyla is a new type of treatment for HER2-positive breast cancer that is referred to as an antibody-drug conjugate (ADC). It is comprised of the anti HER2-drug Herceptin which is attached to a chemotherapy agent. The Herceptin portion of Kadcyla binds to the HER2-protein and the chemotherapy agent is delivered directly to the cancer cell.

Pivotal results from the EMILIA trial ultimately led to the approval of Kadcyla. The EMILIA trial consisted of 991 women who had advanced, HER2-positive breast cancer. All patients had received prior treatment consisting of Herceptin plus a taxane (class of chemotherapy agent).

On the EMILIA trial, patients randomly received treatment with either Kadcyla alone, or Tykerb plus the chemotherapy agent Xeloda® (standard therapy). Patients were treated until their cancer progressed or they were not able to tolerate side effects of therapy.

Median survival time without cancer progression was 9.6 months for patients treated with Kadcyla, compared with 6.4 months for those treated with Tykerb/Xeloda.
Overall median survival time was 30.9 months for patients treated with Kadcyla, compared with 25.1 months for those treated with Tykerb/Xeloda.
The most common side effects associated with Kadcyla were nausea, muscle and joint pain and low levels of platelets (thrombocytopenia). Fewer patients experienced severe side effects with Kadcyla than with Tykerb/Xeloda.
Patients with advanced, HER2-positive breast cancer may wish to speak with their physician regarding treatment with Kadcyla. A patient assistance program for those who are not able to pay for Kadcyla has been established, with information here:


United States Food and Drug Administration. FDA approves new treatment for late-stage breast cancer. 2/22/2013.
Genentech. FDA Approves Genentech’s Kadcyla (Ado-Trastuzumab Emtansine), the First Antibody-Drug Conjugate for Treating Her2-Positive Metastatic Breast Cancer.