Phase II Study With the Trifunctional Antibody Ertumaxomab to Treat Metastatic Breast Cancer After Progression on Trastuzumab Therapy

Key Inclusion Criteria:

Women ≥ 18 years, Negative pregnancy test at screening and life expectancy of at least 3 months
metastatic (stage IV) and not curable adenocarcinoma of the breast
Measurable disease, defined as at least one lesion that is measurable in one dimension (RECIST)
HER-2 overexpression 3+ or 2+ FISH positive
Patients must have received one prior therapy with trastuzumab as last treatment before entry into the study. If trastuzumab was given as single agent treatment, patients must have received prior chemotherapy for metastatic disease
Trastuzumab has been discontinued before study entry
disease had progressed during or after trastuzumab therapy
Eastern Cooperative Oncology Group (ECOG)performance score of ≤ 2
Adequate hematological, liver and kidney function

Key Exclusion Criteria:

Women who are pregnant or breast feeding
Any history or symptoms indicative of brain or central nervous system metastases
Prior diagnosis of any malignancy not cured by surgery alone less than 5 years before study entry (except in situ carcinoma of the cervix or adequately treated basal cell carcinoma of the skin)
Human anti-murine antibody positive or hypersensitivity to murine proteins and any other component of the study drug
Known autoimmune diseases, Human immunodeficiency virus (HIV), hepatitis B or C infection as well as other acute or chronic infection or other concurrent non-malignant co-morbidities that are uncontrolled
Any concurrent chemotherapy, hormonal therapy, immunotherapy or corticoid therapy
Concurrent antibiotic treatment
Any concurrent investigational treatment for metastatic disease

Cardiovascular exclusion criteria:

Unstable or uncontrolled pectorial angina
Myocardial infarction during the last 6 months
Valvular heart disease that requires treatment
Cardiomyopathy (congestive, hypertrophic or restrictive)
Acute myocarditis
Congestive heart failure (CHF): dyspnea, clinically or radiologically diagnosed
Left ventricular ejection fraction (LVEF)outside institution's normal range based on echocardiography at rest
Left ventricular diameter > 56 mm based on M-mode echocardiography at rest
Arrhythmias that require treatment (atrioventricular block II/III degree, atrial fibrillation, ventricular tachycardia)
Poorly or uncontrolled hypertension, asthma, seizures, allergies, pulmonary dysfunction