Neoadjuvant tislelizumab plus nab-paclitaxel and carboplatin for triple-negative breast cancer: a multicenter, open-label, phase II cTRIO study

Background To investigate the efficacy and safety of adding tislelizumab to neoadjuvant chemotherapy with nab-paclitaxel and carboplatin (TP) followed by adjuvant tislelizumab for early TNBC to explore the optimal neoadjuvant chemotherapy backbone and courses. MethodsThe cTRIO study (ChiCTR2100041675) is a multicenter, prospective, open-label phase II trial across 8 sites in China, evaluating the efficacy and safety of neoadjuvant tislelizumab plus TP followed by adjuvant tislelizumab in patients with early triple-negative breast cancer (TNBC).We included women aged 18 years with histologically confirmed early TNBC defined by estrogen receptor immunohistochemistry (IHC) with T1 N1-3 or T2-4 N0-3 stage.Participants received six cycles of neoadjuvant tislelizumab (200 mg on day 1) plus nab-paclitaxel and carboplatin (TP; 125 mg/m 2 on days 1 and 8), definitive surgery 3-6 weeks after completion of neoadjuvant therapy, followed by adjuvant tislelizumab every 3 weeks for 1 year.The primary endpoint was pathologic complete response (pCR).Findings Sixty-two patients were enrolled from March 2021 to October 2022, including 44 cases with programmed cell death ligand 1 (PD-L1) positive and 9 cases at N3.At final analysis, 35/62 patients had achieved pathologic complete response (pCR, 56%; 95% confidence interval [CI], 43%-69%), with 33% (3/9) of N3 cases achieving pCR.The 3-year EFS and OS rates were 82.2% (95% CI, 70.2%-89.7%)and 87.7% (95% CI, 75.6%-94.0%),respectively.The incidence rates of grade 3 treatment-related adverse events (TRAEs) and grade 3 immune-related adverse events (irAEs) were 53% (33/62) and 5% (3/62), respectively.Patients with a higher PD-L1 combined positive score were less likely to experience relapse (P = 0.0090).Interpretation Despite being a de-escalating and anthracycline-free neoadjuvant treatment approach, the triplet combination therapy showed promising efficacy and safety, signifying a crucial step toward the optimization of chemoimmunotherapy for early TNBC.