P-60 Neoadjuvant nedaplatin and paclitaxel regimen with concurrent radiotherapy for esophageal squamous cell carcinoma: A single-arm phase II clinical trial

Neoadjuvant chemoradiotherapy (CRT) improved outcomes in patients with locally advanced resectable esophageal squamous cell carcinoma (ESCC). We aimed to evaluate the efficacy and safety of concurrent nedaplatin plus paclitaxel with radiotherapy for the neoadjuvant treatment in locally advanced ESCC. Locally advanced ESCC patients were included and administrated with 2 cycles of paclitaxel or albumin-bound paclitaxel and nedaplatin with concurrent radiotherapy (41.4-50.4Gy) in the neoadjuvant setting. Surgery was performed within 6-8 weeks after the completion of CRT. Immunohistochemical staining was conducted on preoperative biopsies and surgical specimens of resected patients. The primary endpoint was pathological complete response (pCR) rate. Of 49 eligible patients, 33 underwent surgery with pCR rate of 30.1%. For the whole cohort, the median overall survival (OS) was 22.2 months. The most common serious adverse event was leukopenia (30.6%). For the resected patients, OS was inferior in patients with positive postoperative lymph nodes (HR 5.80 ,95%CI 1.56-21.47, log rank p=0.003). And, higher FOXP3 expression before (HR 0.14 ,95%CI 0.02-1.29, log rank p=0.045) and after (HR 0.29 ,95%CI 0.08-1.08, log rank p=0.050) CRT contributed to favorable outcomes. Increased TIGIT after treatment was associated with poor prognosis in the resected patients (HR 7.95 ,95%CI 0.87-72.63, log rank p=0.031). Concurrent nedaplatin plus paclitaxel with radiotherapy was a promising induction regimen. Higher FOXP3 expression and decreased of TIGIT were associated with favorable efficacy of neoadjuvant CRT. ChiCTR1900024628.