IMP321 Plus First-line Paclitaxel in Metastatic Breast Carcinoma

Inclusion Criteria: * Patients with stage IV breast adenocarcinoma, histologically proven by biopsy of the primary tumor and/or a metastasis. * Female not pregnant (or with negative pregnancy test) or male. * Fertile patients must use effective contraception during and for 3 months after drug administration. * 18 years or above. * ECOG performance status 0-1. * Expected survival longer than three months. * Resolution of toxicity of prior therapy to grade \< 2 (except alopecia). * With or without prior adjuvant or neoadjuvant chemotherapy (authorized). * With or without hormone therapy in adjuvant and/or the advanced setting (authorized). * Evidence of measurable disease as defined by Response Evaluation Criteria in Solid Tumors (RECIST). * Biphosphonate therapy must have started at least 4 weeks prior to first dosing of the study drug. * Asthma or chronic obstructive pulmonary disease allowed provided daily systemic corticosteroid therapy is not required. * Total white cell count ≥ 3.109/L. * Platelet count ≥ 100.109/L. * Hemoglobin \> 9 g/dL or \> 5.58 mmol/L. * Serum creatinine \< 160 µmol/L. * Total bilirubin \< 20 mmol/L, except for familial cholemia (Gilbert's disease). * Serum ASAT and ALAT \< 3 times the upper limit of normal or \< 5 times upper limit of normal if liver metastases are present. * Able to give written informed consent and to comply with the protocol. Exclusion Criteria: * Prior chemotherapy for metastatic breast adenocarcinoma. * Disease-free interval \< 12 months from last dose of adjuvant chemotherapy. * Prior high-dose chemotherapy requiring hematopoietic stem cell rescue. * Inflammatory carcinoma. * Systemic chemotherapy, hormone or endocrine therapy given as breast cancer therapy within 30 days prior to first dosing of the study drug. * Any investigational drug within 30 days prior to first dosing of the study drug. * Candidate for treatment with trastuzumab or administration of trastuzumab within 30 days prior to first dosing of the study drug. * Known cerebral or leptomeningeal metastases. * Pregnancy or breast feeding. * Serious intercurrent infection within the 30 days prior to first dosing of the study drug. * Motor or sensory peripheral neuropathy ≥ 2 according to the National Cancer Institute criteria. * Congestive heart failure. * Active acute or chronic infection. * Active autoimmune disease requiring immunosuppressive therapy. * Known HIV positivity. * Life threatening illness unrelated to cancer. * Previous malignancies within the last two years other than breast carcinoma, successfully treated squamous cell carcinoma of the skin or in situ carcinoma of the cervix treated with cone biopsy. * Previous history of major psychiatric disorder requiring hospitalization or any current psychiatric disorder that would impede the patient's ability to provide informed consent or to comply with the protocol. * Corticosteroids unless used as substitutive therapy or before each injection of paclitaxel. * Past history of severe allergic episodes and/or Quincke edema. * Past or present history of any organic disorder likely to modify absorption, distribution or elimination of the study drug. * Alcohol or substance abuse disorder. * Radiotherapy within the 30 days prior to first dosing of the study drug.