A multi-center, phase III clinical trial is seeking women with recurrent, locally advanced or metastatic HER2 positive breast cancer that has stopped responding to treatment after at least two prior rounds of HER2-targeted therapy.
The study will evaluate a new type of HER2-targeted therapy, trastuzumab emtansine (T-DM1), versus treatment of the doctor’s choice. Participants in each of two groups will be compared to evaluate the safety and effectiveness of T-DM1 to other treatments.
This clinical trial is sponsored by Genentech, the company that makes trastuzumab emtansine.
Background and Reason for the Study
HER proteins regulate cell growth, as well as other cell functions. When there is too much HER2 protein, cells grow uncontrollably, especially in some breast cancers. Trastuzumab (Herceptin) binds with cancer cells, targeting the HER2 protein and interrupting uncontrolled cell growth.
Trastuzumab emtansine links trastuzumab with the chemotherapy medicine mertansine (DM1). It works by first binding to the cancer and interfering with cell growth. Then it delivers the DM1 chemotherapy medicine directly into the cancer cells, destroying them.
There is no standard of care for HER2 positive breast cancer that has not responded to available HER2-targeting treatments. Researchers are looking at new therapies like trastuzumab emtansine to see if they might be more effective than the others available.
Goals of the Trial
The primary goals of this trial are to assess objective response rate, or how much the cancers shrink because of treatment, and overall survival, how long participants live after enrolling in the study.
Researchers will also consider how long the cancer goes without growing (progression-free survival), how long the cancer continues to shrink, the benefit of treatment, and survival rates at the six-month and one-year marks.
Structure of the Trial
The researchers seek to enroll 795 people from 199 study sites worldwide who will be randomly assigned to one of two treatment groups. One group will get trastuzumab emtansine intravenously (by vein) once every 21 days. The other group will get chemotherapy, hormonal therapy, a biologic medicine or a HER2-targeted therapy, based on the doctor’s choice.
The trial is open-label, which means both researchers and participants know who is getting which treatment.
Am I Eligible?
If you have recurrent, locally advanced or metastatic HER2 positive breast cancer that cannot be removed with surgery, you may be eligible for this study. You must have had at least two previous treatments with an anthracycline, trastuzumab, a taxane, lapatinib (Tykerb) or capecitabine (Xeloda), and the cancer did not shrink or continues to grow.
You cannot participate if you have untreated or active brain metastases, or you received chemotherapy or trastuzumab within 21 days or lapatinib within 14 days. You cannot have participated before in a T-DM1 trial.
What Else Do I Need to Know?
Like trastuzumab, TDM-1 can prompt severe heart problems. More common side effects include fatigue, nausea, flu-like symptoms, liver problems and low platelet counts that may cause bruising or bleeding.
