Neoadjuvant tislelizumab plus nab-paclitaxel and carboplatin for triple-negative breast cancer: a multicenter,...

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.

The 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/m² 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).

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).

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.

This study was supported by BeOne Medicines, Ltd.