179P Neoadjuvant Camrelizumab Plus Nab-Paclitaxel and Epirubicin for Early Triple-Negative Breast Cancer: A Single-Arm, Open-Label, Phase II Study

Immune checkpoint inhibitors have shown promising efficacy in patients with triple-negative breast cancer in the neoadjuvant and metastatic settings. Whether the addition of anti-PD1 antibody camrelizumab to chemotherapy would increase the rate of pathological complete response (pCR) for early triple-negative breast cancer is unclear. In this phase 2 study, eligible patients were aged 18 to 60 years, had previously untreated early triple-negative breast cancer, and Eastern Cooperative Oncology Group performance status of 0-1. Patients received 6 cycles of camrelizumab (200 mg, once every 3 weeks) plus nab-paclitaxel (125 mg/m2, on days 1, 8, and 15) and epirubicin (75 mg/m2, once every 3 weeks), followed by surgery. The primary endpoint was the total pCR (tpCR; ypT0/is, ypN0) rate. Using a Simon’s two-stage design, 4 of 9 patients were required to achieve tpCR in the first stage, with a prespecified tpCR rate of 55% before proceeding to the second stage. A total of 39 participants was required for the study. Eight out of 9 patients achieved tpCR in the first stage, reaching the threshold for the second stage. From January 2020 to April 2021, a total of 25 patients was enrolled and 15 received surgery after the completion of neoadjuvant therapy. tpCR was observed in 86.7% (13/15) of patients and the trial accrual is ongoing. The most common grade 3 or 4 treatment-related adverse events were leucopenia (68%), neutropenia (40%), and anemia (16%). No treatment-related deaths occurred. Camrelizumab plus nab-paclitaxel and epirubicin resulted in higher rate of tpCR in patients with early triple-negative breast cancer and had a manageable toxicity profile. Further study is warranted to validate our findings.