TBCRC 023: A Randomized Multicenter Phase II Neoadjuvant Trial of Lapatinib Pus Trastuzumab, With or Without Endocrine Therapy for 12 Weeks vs. 24 Weeks in Patients With HER2 Overexpressing Breast Cancer
Breast cancer cells have certain characteristics or traits--these traits are called
biomarkers. There are three biomarkers that help doctors decide which treatment to give any
given patient. These biomarkers are the estrogen receptor (ER), progesterone receptor (PgR),
and HER2 protein. Breast cancer cells that have a large number of estrogen or progesterone
receptors are called ER and/or PgR positive. Cancers that are ER and/or PgR positive use the
hormones estrogen and progesterone to help them grow. Not all breast cancers are ER or PgR
positive. Patients are being asked to take part in this study that have a special type of
breast cancer called HER2 positive breast cancer. HER2-positive breast cancer is a breast
cancer that tests positive for a protein called human epidermal growth factor receptor-2
(HER2). HER2 is located on the outer surface of a cancer cell. The HER2 protein sends a
signal to the inside of the cancer cells telling it to grow and divide.
Two medications that directly target this HER2 protein. One is called
trastuzumab(Herceptin), and the other is called lapatinib (Tykerb). Both medications are
FDA-approved for the treatment of women with HER2+ breast cancer. Each medication attaches
to the protein so that it can no longer function. Once the protein stops working, the cancer
cells can no longer make copies of themselves. This makes cancer shrink. Both drugs target
HER2; however each drug works a little bit differently.
Some patients respond better to Herceptin, and some patients respond better to Tykerb. Right
now, we are not sure why some patients respond to one drug but do not respond to the other
drug. One possibility is that in some patients, the HER2 protein finds another way to send
its message to the inside of the cell (similar to a road detour). For example, when one path
is "closed" because the drug is blocking it, the HER2 protein finds a different way to send
its signal. We think that we can completely block the HER2 protein by giving patients both
Tykerb and Herceptin.
Some patients with HER positive breast cancer are also ER and/or PgR positive. Even after
HER2 is completely blocked, these types of cancer cells can still grow by using the estrogen
or progesterone receptor. If a patient is told they are ER and/or PgR positive, they will
also take an anti-estrogen pill along with Tykerb and Herceptin. We think that we can stop
cancer growth more completely by blocking both the HER2 protein and the ER/PR receptors.
Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment
To evaluate the rate of pathologic complete response, defined as no residual invasive cancer in the breast, after 12 or 24 weeks of lapatinib/trastuzumab with or without endocrine therapy.
We propose a randomized multicenter neoadjuvant clinical trial in HER-2 overexpressing breast cancer patients with 12 vs. 24 weeks of lapatinib plus trastuzumab, with or without endocrine therapy, during which serial cancer tissue samples will be obtained for molecular studies in relation to tumor response. The patients will receive either 12 or 24 weeks of therapy to determine the pathologic complete response rate to this combined targeted therapy regimen, without the addition of any cytotoxic chemotherapy.
Mothaffar Rimawi, MD
Baylor College of Medicine
United States: Food and Drug Administration
|Vanderbilt University Medical Center||Nashville, Tennessee 37232-2516|
|Duke University||Durham, North Carolina 27710|
|Dana Farber Cancer Institute||Boston, Massachusetts 02115|
|University of Chicago||Chicago, Illinois 60637|
|Indiana University||Indianapolis, Indiana 46202|
|Johns Hopkins||Baltimore, Maryland 21231|
|University of Alabama - Birmingham||Birmingham, Alabama 35294|
|Baylor College of Medicine Lester and Sue Smith Breast Center||Houston, Texas 77030|