The aim of the study is to establish a feasible combination of bendamustine and paclitaxel in a weekly schedule. The two agents have different toxicity profiles and are well tolerated when given in a weekly fashion. The combination might be of special interest for elderly patients with hormone insensitive breast cancer

Inclusion Criteria:

• Written informed consent must be obtained and documented according to the local regulatory requirements prior to beginning specific protocol procedures;
• Pathological confirmed primary carcinoma of the breast.
• Locally advanced or metastatic disease
• Up to one previous palliative chemotherapy that did not contain docetaxel or paclitaxel. Previous adjuvant treatment with taxanes is allowed when the last application of the taxane was given at least 1 year before entering the trial.
• Patients must have either measurable or non-measurable lesions according to the WHO criteria
• At least 4 weeks since radiotherapy, with full recovery. The measurable disease must be completely outside the radiated field or there must be pathological proof of progressive disease.
• Complete radiological and clinical tumor assessment within 4 weeks prior to registration performed as clinically indicated
• Karnofsky-Index ≥ 60 %
• Age ≥ 18 years
• Absolute neutrophil count ≥ 1,500 cells/µl, platelets ≥ 100,000/µl, and hemoglobin ≥ 9 g/dl
• Bilirubin within normal limits; evaluation of transaminases and alkaline phosphatase ≤ 5x upper normal limit
• Serum creatinine ≤ 2.0 mg/dl
• Normal left ventricular ejection fraction (LVEF) by echocardiogramme
• Patients of childbearing potential, pregnancy test must be negative
• If fertile effective contraception must be used throughout the study

Exclusion Criteria:

• Known or suspected hypersensitivity reaction to the investigational compounds or incorporated substances;
• Concurrent immunotherapy or hormonal treatment for cancer (Bisphosphonates may be continued)
• Symptomatic parenchymal brain metastases not responding to treatment
• Life expectancy less than 3 months
• Other serious illness or medical condition that may interfere with the understanding and giving of informed consent and the conduct of the study
• Concurrent treatment with other experimental drugs or any other anti-cancer therapy within the last 28 days;
• History of congestive heart failure or other significant uncontrolled cardiac disease
• Pregnant or nursing women