Impact of Pegfilgrastim on Trastuzumab Anti-tumor Effect and ADCC in Operable HER2+ Breast Cancer Breast Cancer

The duration of the neoadjuvant treatment period is planned to be 12 weeks (4 cycles of 3 weeks), except in case of Inacceptable toxicity, or Patient decision, or Withdrawal of consent, or Clinical/radiological signs of disease progression.This neoadjuvant treatment period will be ended with a short term safety visit (STSVNeo) to be scheduled 28 days after the last dose of study treatments (considering the latest study treatments administered). Following the STSVNeo, patients will undergo surgery as per usual practice and pathological response will be centrally assessed by a referent pathologist blinded for the treatment arms.Following surgery, all patients will be treated in the adjuvant setting with trastuzumab administered every 3 weeks for up to 12 months in both arms with clinical assessments every 3 months (cf. Réseau régional de Cancérologie, http://espacecancer.sante‐ra.fr/Pages/Accueil.aspx). In case of RH+ disease, endocrine therapy may be initiated as per standard treatment guidelines.This adjuvant treatment period is planned for a maximum of 12 months; except in case of Inacceptable toxicity, or Patient decision, or Withdrawal of consent, or Clinical/radiological signs of disease progression. All randomized and treated patients will be followed‐up for relapse and survival for at least 15 months post‐randomization (i.e. 1 year post‐surgery). A total of 90 patients will be randomized in the study. (45 per arm). All the data concerning the patients will be recorded in the electronic case report form (eCRF) throughout the study serious adverse event (SAE) reporting will be also paper‐based by e‐mail and/or Fax. The sponsor will perform the study monitoring and will help the investigators to conduct the study in compliance with the clinical trial protocol, Good Clinical Practices (GCP) and local law requirements