Conditions: Breast Cancer
Keywords: HER2-positive breast cancer Herceptin trastuzumab
Allocation: NON_RANDOMIZED | Intervention model: PARALLEL
Enrollment: 87
Healthy volunteers: no

Brief summary:
In this research study we are studying the effects of the combination of lapatinib plus Herceptin in subjects with breast cancer that has spread outside of the breast. We are also studying whether positron emission tomography (PET/CT) scans can predict which participants will benefit from the study treatment. Finally, we are studying genes and proteins in the tumor tissue that may lead to sensitivity or resistance to Herceptin, and to the combination of Herceptin plus lapatinib. Lapatinib is a compound that may stop cancer cells from growing. Other research studies suggest that lapatinib in combination with Herceptin may help to shrink or stabilize breast cancer.

Detailed description:
* Participants will be asked to undergo a biopsy of an area of the body where the cancer has spread.
* Participants will be given a study medication-dosing calendar for each treatment cycle. Each treatment cycle lasts four weeks during which time you will be taking lapatinib, once per day.
* Participants will receive Herceptin once every week or once every 3 weeks through a vein.
* During all treatment cycles a physical exam will be performed and questions about the participants general health will be asked. Blood tests including chemistry and hematology will be performed to measure additional effect of the study drug and disease status. Photographs may be taken of the tumor to assess the response of the tumor to treatment.
* CT scans will be repeated every 8 weeks to assess the effect of the study treatment on the cancer. Either a MUGA scan or echocardiogram will be performed 8 weeks and 16 weeks after the participant starts the study treatment.
* Participants will remain on this research study for as long as they are benefiting from the study treatment.

Arms:
arm 1: This cohort is made up of participants without prior trastuzumab for MBC. Adjuvant or neoadjuvant trastuzumab was allowed, if the interval from trastuzumab completion to recurrence exceeded 1 year.

1000 mg daily Lapatinib

2 mg/kg weekly or 6 mg/kg every 3 week dose of trastuzumab arm 2: This cohort is made up of participants with one to two lines of chemotherapy for metastatic disease with at least one trastuzumab-containing regimen or patients who recurred within 12 months of adjuvant or neoadjuvant trastuzumab with up to one line of metastatic trastuzumab-based therapy

1000 mg daily Lapatinib

2 mg/kg weekly or 6 mg/kg every 3 week dose of trastuzumab

Interventions: intervention 1: Lapatinib intervention 2: Herceptin
Intervention descriptions: intervention 1: None intervention 2: None

Protocol document: