Metastatic Breast Cancer (MBC)

The purpose of this research is to learn if the CellSearch Circulating Tumor Cells (CTC) test can help doctors in making decisions about treatment and monitoring of breast cancer. The test consists of diagnostic CTC counts (enumeration) and expression of biomarkers Human Epidermal growth factor Receptor 2 (HER2), Estrogen Receptor (ER), and programmed death-ligand 1 (PD-L1) and cell free DNA/RNA (cfDNA/RNA) analysis.

This multicenter, randomized, open, parallel positive control study compares the clinical efficacy and safety of paclitaxel polymeric micelles for injection with TPC in HER2- MBC subjects who have failed ≥2 to≤4 previous chemotherapy regimens. Treatment Protocol: Subjects are randomized into paclitaxel polymeric micelles for injection group and the Physician's Choice (TPC) group by the proportion of 1:1. Randomization is stratified according to three factors: number of lines of previous treatment for metastatic disease (2 or 3/4 lines), receptor status (triple-negative, non-triple-negative), and visceral metastasis (yes/no). Progression-free survival (PFS) is the main efficacy indicator in this study. Treatment Group: Subjects are given paclitaxel polymeric micelles for injection, three weeks constitutes one cycle of treatment. Control Group: Physician's Choice Group, subjects are given Eribulin Mesilate injection; or capecitabine tablets; or gemcitabine hydrochloride for injection; or vinorelbine tartrate injection; or paclitaxel (albumin-bound). Three or four weeks constitutes one cycle of treatment. If subject does not develop disease progression after 6 cycles of dosing, the subject continues treatment until disease progression (RECIST 1.1) or develops an intolerable toxicity, initiation of a new anti-cancer drug, withdrawal from the study, death, or loss of follow-up. Superiority design is used in this study, progression-free survival (PFS) is the main efficacy indicator. Assuming α = 0.0249(unilateral, adjusted test level), power=80%, the median PFS of the treatment group is 6.0 months, the median PFS of the control group is 3.7 months, the enrollment period is 12 months, and the study period is 24 months. Using PASS (version 11.0) for calculation, a total of 152 subjects (76 in each group) are required to meet the statistical significance between the treatment group and the control group. In consideration of case expulsion, enlarged by 10%, a total of 168 subjects (84 in each group) are required.