The primary objective of this study is to compare disease-free survival (DFS) of patients with operable breast cancer randomised to treatment with standard adjuvant chemotherapy plus moxifloxacin or placebo.

This is a multicenter, randomised, double-blind, placebo-controlled, phase 3 clinical trial. The main purposes of this study are to examine the efficacy and safety of standard adjuvant chemotherapy plus moxifloxacin or placebo as care for patients with operable breast cancer. This study is designed to recruit up to 520 subjects.

Inclusion Criteria:

1. Have provided written and signed informed consent;
2. Histologically confirmed invasive ductal carcinoma;
3. Planned to received (neo)/adjuvant chemotherapy;
4. Eastern Cooperative Oncology Group (ECOG) score of 0 to 1;
5. Normal blood routine, liver and kidney functions within 1 week before enrollment in this study;
6. Women of childbearing age have a negative serum or urinary pregnancy tests prior to enrollment in this study; Pre-menopause women are contracepted with medically acceptable methods during the study period.
7. Compliance with the study protocol.

Exclusion Criteria:

1. Pregnant or breast feeding;
2. Eastern Cooperative Oncology Group (ECOG) score ≥ 2;
3. Hypersensitivity to moxifloxacin or quinolones compounds;
4. Concomitant with other antitumor therapies or participating in other clinical trials;
5. Have a history of heart disease, such as arrhythmia, conduction block, S-T segment elevation, ischemic heart disease, or congenital heart disease;
6. Severe uncontrolled co-infection, or severe metabolic disorders;
7. A clear past history of neurological or psychiatric disorders, including epilepsy or dementia;
8. Poor compliance, unwillingness or inability to follow protocol to continue the study;
9. Any circumstances in which the investigator deemed the subject unsuitable for enrollment in this study.

We decided to not share our individual participant data (IPD) to other researchers.