Neoadjuvant

Background: According to preclinical experiments, Methods: Eligible patients aged 18 years or older with previously untreated HER2-negative stage II-III breast cancer were enrolled and randomly assigned at a 1:1 ratio to receive neoadjuvant chemotherapy with PA-MSHA or a placebo. The Response Evaluation Criteria in Solid Tumors (RECIST) was used to assess clinical response every 2 cycles. The primary endpoint was the objective response rate (ORR) based on the clinical response following neoadjuvant chemotherapy. Results: A total of 75 patients were randomly assigned to either the PA-MSHA group (37 patients) or the control group (38 patients). The ORR was found to be significantly higher in the PA-MSHA group compared with the control group [86.5% versus 60.5%; rate difference 26.0; 95% confidence interval (CI): 5.9-43.5%; P=0.011]. The pathological complete response (pCR) and survival outcomes did not differ significantly between the 2 groups. Patients with immune-related adverse events (irAEs) appeared to benefit from the PA-MSHA treatment, with greater disease-free, relapse-free, and overall survival. The application of PA-MSHA to neoadjuvant chemotherapy did not increase the incidence of severe adverse events. Moreover, the addition of PA-MSHA increased serum interferon-γ levels and the percentage of peripheral blood T cells, CD8 Conclusions: The addition of PA-MSHA to neoadjuvant chemotherapy is an effective alternative regimen for HER2-negative breast cancer. Patients with irAEs caused by PA-MSHA may obtain more benefits from this treatment. Trial Registration: Chinese Clinical Trial Registry ChiCTR-TRC-10000794.