Amoxicillin-clavulanate Alone or in Combination With Ciprofloxacin in Low-Risk Febrile Neutropenic Adult Patients: A Prospective, Double-blind, Randomized, Non-Inferiority Multicenter, Phase III Clinical Trial.

Inclusion Criteria: * Patient ≥ 18 years old * Treated for a solid cancer or a hematological malignancy * Presented with low-risk\* febrile neutropenia due to chemotherapy with an expected duration of neutropenia ≤ 7 days * Neutropenia is defined by an absolute neutrophil count ≤ 500/mm3. * Fever is defined by temperature ≥ 38.3° or ≥ 38° twice during a 1-hour interval. * Signing informed consent \*Low risk is defined by MASCC score ≥ 21 Exclusion Criteria: * Hypersensitivity to the active substances: amoxicillin-clavulanic, ciprofloxacin, penicillins, to other quinolones or to one of the excipient * History of severe immediate hypersensitivity reaction to another beta-lactam * History of jaunditis/hepatic impairment related to amoxicillin/clavulanic * Concomitant administration of ciprofloxacin and tizanidine. * Clinical signs of focal infection including history of untreated dental abscess. * Signs of sepsis or organ failure. * Severe immune deficiency other than the current cancer, except controlled-HIV infection * Gastrointestinal symptoms requiring intravenous treatment (mucositis, vomiting, severe diarrhea...). * Known aminotransferase serum levels \> 5 x normal values. * Known renal insufficiency defined as creatinine clearance of \< 30 mL/min (MDRD). * Antibiotherapy within 24h before enrollment. Prophylactic use of amoxicillin is an exclusion criterium whereas prophylactic use of trimethoprim-sulfamethoxazole (cotrimoxazole) and penicillin G (Oracilline®) are not and will be considered in the analysis. * History of infection or colonization due to bacteria resistant to experimental drugs in the previous year * Can be enrolled in the study only once. * Patients not benefiting from a Social Security scheme or not benefiting from it through a third party. * Persons benefiting from enhanced protection, namely minors, persons deprived of their liberty by a judicial or administrative decision, persons staying in a health or social institution, adults under legal protection, and finally patients in emergencies * Pregnant or breastfeeding women, women at age to procreate and not using effective contraception (either hormonal / mechanical : oral, injection, subcutaneous, implantable, intrauterine device, or surgical : tubal ligation, hysterectomy, total ovariectomy).