A phase 2 study has indicated that the combination of tislelizumab, an anti-PD-1 antibody, with neoadjuvant chemotherapy shows promising results in treating locally advanced esophageal squamous cell carcinoma (LA-ESCC). The study, published in Frontiers in Immunology, evaluated the safety and effectiveness of this approach in patients with resectable LA-ESCC.
The trial enrolled 30 patients with clinical stages II-IVA (T3-T4 and/or node positive) LA-ESCC. Participants received neoadjuvant tislelizumab and chemotherapy every 3 weeks for 4 cycles, followed by surgery and adjuvant tislelizumab for 9 months. The primary endpoint was the pathological complete response (pCR) rate, while secondary endpoints included R0 resection, disease-free survival (DFS), adverse events (AE), and biomarkers for predicting efficacy.
Key Findings
Of the 30 patients enrolled, 25 completed neoadjuvant chemoimmunotherapy and underwent surgery. The R0 resection rate was 96%. The pCR rate was 44%, and the major pathological response (MPR) rate was 52%. The 6-month and 1-year DFS rates were 100% and 75.3%, respectively. Grade 3-4 treatment-related adverse events (TRAEs) occurred in 43.3% of patients, and 5 patients developed severe immune-related adverse events (irAEs).
Biomarker Analysis
Further exploration revealed that specific peripheral lymphocyte subsets increased significantly after 2 cycles of neoadjuvant therapy in patients who achieved pCR. This suggests the potential importance of dynamically monitoring circulating lymphocyte subsets as a predictive marker for treatment efficacy.
Clinical Implications
The study suggests that perioperative tislelizumab combined with neoadjuvant chemotherapy can achieve an encouraging pCR rate and demonstrates a manageable safety profile in patients with potentially resectable ESCC. These findings support further investigation of this combination as a treatment option for LA-ESCC. The authors also highlight the importance of monitoring circulating lymphocyte subsets during treatment to potentially predict patient response.
