Trilaciclib in Patients With Early-Stage HR-negative Breast Cancer Receiving Adjuvant Chemotherapy

The goal of this multicenter, two-cohort, exploratory clinical trial is to evaluate patients with early stage hormone receptor-negative breast cancer receiving standard adjuvant chemotherapy after surgery. The main question it aims to answer is: • The efficacy and safety of trilaciclib administered before standard adjuvant chemotherapy regimen using the incidence of grade 3/4 neutropenia as the primary efficacy endpoint. Participants will divide into two treatment cohorts according to molecular typing type: * Cohort A will be planned to include post-operative triple-negative breast cancer(TNBC) patients with lymph node positive or tumor \> 2 cm treated with trilaciclib combined with epirubicin and cyclophosphamide followed by weekly paclitaxel; * Cohort B will be planned to include HER2-positive/HR-negative breast cancer patients with axillary node positive or tumor \> 2 cm treated with trilaciclib combined with docetaxel, carboplatin and trastuzumab with or without pertuzumab.