Andrew J. Roth
Courtesy of Genentech
The FDA has approved ado-trastuzumab emtansine (Kadcyla) for patients with HER2-positive, late-stage breast cancer. T-DM1 is being approved with a Boxed Warning that the drug can cause liver toxicity, heart toxicity, and death.
T-DM1 is an anti-HER2 therapy approved for use in patients who received prior treatment with trastuzumab (another anti-HER2 agent) and taxane-based chemotherapy. HER2 is a protein involved in normal cell growth and when observed in an increased amount, contributes to cancer cell survival.
“Kadcyla delivers the drug to the cancer site to shrink the tumor, slow disease progression, and prolong survival. It is the fourth approved drug that targets the HER2 protein,” Richard Pazdur, MD, director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research, said.
T-DM1 was granted priority review and received approval based on the EMILIA trial. In the phase III trial, 991 patients were randomized to receive T-DM1 alone or lapatinib plus capecitabine until the disease progressed or side effects became intolerable. Patients in the T-DM1 arm had a median progression-free survival of 9.6 months versus 6.4 months in the lapatinib plus capecitabine arm (HR = 0.65; 95% Cl, 0.55-0.77; P
< .001). Patients in the T-DM1 arm also experienced an overall survival benefit, at a median of 30.9 months compared to 25.1 months in the lapatinib plus capecitabine arm.
The most common side effects reported were nausea, fatigue, pain in the muscles or joints, thrombocytopenia, increased levels of liver enzymes, headache, and constipation. T-DM1 can also cause severe life-threatening birth defects, according to the FDA.
“Kadcyla is an antibody-drug conjugate representing a completely new way to treat HER2-positive metastatic breast cancer, and it helped people in the EMILIA study live nearly six months longer,” Hal Barron, MD, chief medical officer and head, Global Product Development, Genetech, said.
In addition to trastuzumab, lapatinib, and pertuzumab, T-DM1 is the fourth anti-HER2 drug to be approved by the FDA. This treatment adds another option for physicians who treat breast cancer, which is the second leading cause of cancer-related death among women, according to the FDA.