Conditions: Breast Cancer
Keywords: Breast Cancer Metastatic PRO Onc Assay FISH Testing HER Negative HER Overexpression HER Activation
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 283
Healthy volunteers: no

Brief summary:
This trial will evaluate the clinical significance of the PRO Onc assay and will assess the efficacy of HER2-targeted therapy in patients with HER2-negative breast cancer who have been identified as having HER2 overexpression/activation by the PRO Onc Assay.

Detailed description:
This two-part trial is designed to evaluate the clinical significance of the PRO Onc assay when used in patients with metastatic HER2-negative breast cancer. The first part of this study will determine the incidence of HER overexpression/activation, as determined by the PRO Onc assay, in patients previously judged to have HER2-negative breast cancer by FISH analysis. Blood specimens will be obtained from patients with HER2-negative breast cancer; CTCs will then be isolated and tested for HER2 overexpression/activation using the PRO Onc Assay. When clinically indicated, fine needle aspiration biopsy will also be obtained and submitted for the PRO Onc Assay. If the incidence of HER2 overexpression/activation, as determined by the PRO Onc Assay, is \>10%, the study will proceed to Part 2. Part 2 of this study will assess the efficacy of HER2-targeted therapy in a group of patients with HER2-negative breast cancer who are identified as having HER2 overexpression/activation by the PRO Onc Assay. Patients will be treated with either trastuzumab or pertuzumab. Patients who progress during the first 8 weeks will have HER2-targeted treatment discontinued and will be removed from study. After 8 weeks, patients who have stable disease will be allowed to add chemotherapy to HER2-targeted therapy. Patients who have an objective response to single-agent, HER2-targeted therapy after 8 weeks will continue single-agent therapy.

Arms:
arm 1: Blood specimens tested for circulating tumor cells followed by systemic treatment based on assay results with either trastuzumab or pertuzumab

Interventions: intervention 1: PRO Onc Assay and Treatment intervention 2: Trastuzumab intervention 3: Pertuzumab
Intervention descriptions: intervention 1: Patients with HER2-negative metastatic breast cancer will be identified, and blood specimens will be obtained from each participant. The PRO Onc Assay will be performed on CTCs isolated from these specimens. When clinically indicated, fine needle aspiration biopsy will also be obtained and submitted for the PRO Onc Assay. intervention 2: 8 mg/kg IV loading dose, followed by 6 mg /kg IV every 3 weeks until progressive disease or unacceptable toxicity with evaluations performed every 8 weeks intervention 3: 840 mg IV loading dose, followed by 420 IV every 3 weeks until progressive disease or unacceptable toxicity with evaluations performed every 8 weeks

Protocol document: