A Three-agent Regimen for Triple Negative Breast Cancer Treatment

Triple-negative breast cancer (TNBC) has a poor prognosis with current treatment options. Novel therapeutic strategies are urgently needed to enhance treatment outcomes for TNBC.

This study evaluated the efficacy of a three-agent regimen compared to existing treatment regimens in a TNBC mouse model, and elucidated its potential mechanisms of action.

The TNBC xenograft tumor mouse model was established using a 4T1 cell line in female BALB/c mice. Mice were treated with the three-agent regimen and other comparative treatments. Tumor volume was monitored to assess the anti-tumor effects. Biochemical and pathological evaluations were conducted to examine the impact of the regimen on anti-tumor immunity, anti- tumor angiogenesis, and tumor cell apoptosis.

The three-agent regimen consisting of SIN+BEV+PAB demonstrated significant anti-tumor efficacy compared to controls, PAB alone, SIN+PAB, and BEV+PAB groups from day 9 of drug administration. The superior anti-tumor effect of SIN+BEV+PAB was primarily attributed to enhanced anti-tumor immunity, evidenced by increased percentages of CD4+ and CD8+ T cells, elevated IFN-γ levels, and decreased percentages of Tregs, reduced levels of TGF-β, IL-6, and IL-10. Additionally, the regimen showed potent anti-angiogenic effects by reducing VEGF expression and micro vessel density (MVD). Furthermore, it promoted tumor cell apoptosis through upregulation of BAX and cleaved caspase3, while downregulating Bcl2.

These findings suggest that the novel three-agent combination of SIN+BEV+PAB may prove beneficial in improving treatment outcomes for patients with TNBC. The development of this regimen, which may be eligible for patent protection, could facilitate its introduction as a new therapeutic option for advanced TNBC in clinical practice.