This study is an open label, non-randomized, fixed dose-escalation phase I study, performed in ambulatory setting with patients receiving as a first line chemotherapy for metastatic breast carcinoma the standard 6 cycles of paclitaxel (80 mg/m² at D1, D8 and D15 of every 4-week cycle). Twenty mg i.v. dexamethasone will be given in the first cycle before each paclitaxel infusion. Corticosteroids will not be administered after the first chemotherapy cycle if the first 3 i.v. infusions of paclitaxel have been well tolerated.~Three IMP321 dose levels (0.25, 1.25 and 6.25 mg) will be evaluated in three cohorts of at lesat 8 patients. At any given dose level the patients will be administered one dose every two weeks for a total of 24 weeks (12 injections in total), separated by 13-day intervals free of IMP321 administration.~The study drug will be given by subcutaneous injection:~Cohort A: 0.25 mg s.c.~Cohort B: 1.25 mg s.c.~Cohort C: 6.25 mg s.c.~The repeated single doses will be administered on D2 and D16 of the 4-week cycles, on the day which follows chemotherapy.~After a screening performed between Week -2 and Day 1, patients will enter the main study period. Upon having completed the 6 cycles of IMP321 treatment at Week 23, they will have an ambulatory 'post-study' examination (at Week 25).~Cohort B will be undertaken once the safety and tolerability results of Cohort A have been satisfactory; the investigator will take his decision for involving the last 8 patients of the study after the 6th administration (Week 13 assessment) of the fifth patient of Cohort A. All cohorts will follow the same schedule~Standard clinical and laboratory safety examinations, CT scan and pharmacodynamic (PD) blood tests will be performed. A complete examination will be carried out at Week 13 (after the 6th drug dosing) and Week 25.
Open label, non-randomized, fixed dose-escalation phase I study, performed in ambulatory setting in patients receiving as a first line chemotherapy for metastatic breast carcinoma the standard 6 cycles of weekly paclitaxel (80 mg/m² at D1, D8 and D15 of a 4-week cycle). Three IMP321 doses (0.25, 1.25 and 6.25 mg) will be tested and given at D2 and D16 of this 4-week cycle, for 6 courses.