Neoadjuvant camrelizumab combined with chemotherapy and apatinib for locally advanced thoracic esophageal squamous cell carcinoma (ESCC): A single-arm, open-label, phase Ib study.

Abstract

4047 Background: Neoadjuvant therapy with PD-1 blockade plus chemotherapy has been found to be effective in the first-line treatment of advanced esophageal cancer. However, evidence of PD-1 blockade combined with chemotherapy as neoadjuvant treatment is limited. This study was designed to investigate the safety and efficacy of camrelizumab, a PD-1 blockade combined with chemotherapy and apatinib as neoadjuvant therapy for locally advanced esophageal squamous cell carcinoma (ESCC). Methods: A regiment of 2–4 cycles of neoadjuvant camrelizumab (200 mg, intravenous, day 1), nab-paclitaxel (150 mg/m2, intravenous, day 1), nedaplatin (50 mg/m2, intravenous, day 1), and apatinib (250 mg, orally, day 2–4) was given to the treatment-naive patients with resectable locally advanced ESCC. The treatments were repeated every 14 days. In this study, six patients were planned to receive two cycles of neoadjuvant therapy as safety assessment, and then 24 patients received four cycles of neoadjuvant therapy, followed by esophagectomy after 4–8 weeks. The primary end points were safety and feasibility. The secondary end points were the rate of major pathologic response (MPR) and pathologic complete response rate (pCR). Results: A total of 30 patients were enrolled, among them, five patients received two planned cycles of neoadjuvant therapy, and one patient missed the second cycle of therapy due to grade 3 ALT elevations. Further, all other 24 patients received four planned cycles of neoadjuvant therapy. A total of 11 patients (11/30, 36.7%) experienced grade 3 neoadjuvant treatment-related adverse events (TRAEs). No grade 4 and grade 5 TRAEs were reported. The most frequent grade 3 TRAEs was neutropenia (7/30, 23.3%). Twenty-nine patients underwent minimally invasive esophagectomy (McKeown procedure) after neoadjuvant therapy. The reason for not undergoing surgery was due to bone metastasis. There were five treatment-related surgical delays that were caused by adverse reactions (hyperglycemia, arthritis, anemia, leukopenia, capillary endothelial proliferation in oral mucosa). Among the 29 patients undergoing esophagectomy, 15 patients (15/29, 51.7%) achieved MPR, including 7 patients with pCR (7/29, 24.1%). Among the 24 patients who received four cycles of neoadjuvant treatment, there were 7 patients with pCR (7/24, 29.2%), and 14 patients with MPR (14/24, 58.3%). No surgery related mortality was documented. Conclusions: Neoadjuvant camrelizumab combined with chemotherapy plus apatinib is a safe and tolerable treatment for patients with locally advanced ESCC, and the MPR and pCR rate are promising. Clinical trial information: ChiCTR1900023880.