Multicenter, Single-arm, Phase II Trial of Camrelizumab and Chemotherapy As Neoadjuvant Treatment for Locally Advanced Esophageal Squamous Cell Carcinoma

Background: Camrelizumab and chemotherapy demonstrated durable antitumor activity with a manageable safety profile as first-line treatment in patients with advanced esophageal squamous cell carcinoma (ESCC). This study aimed to evaluate the safety and efficacy of camrelizumab plus neoadjuvant chemotherapy, using pathologically complete response (pCR) as primary endpoint, in the treatment for locally advanced ESCC.

Methods: Patients with locally advanced but resectable thoracic ESCC, staged as T1b-4a, N2-3 (≥3 stations), and M0 or M1 lymph node metastasis (confined to the supraclavicular lymph nodes) were enrolled. Eligible patients received intravenous camrelizumab (200 mg, day 1) plus nab-paclitaxel (100 mg/m, day 1, 8, 15) and carboplatin (area under curve of 5 mg/mL/min, day 1) of each 21-days cycle, for two cycles before surgery. The primary endpoint is pCR rate in the per-protocol population. Safety was assessed in the modified intention-to-treat population that was treated with at least one dose of camrelizumab.

Results: From November 20, 2019 to December 22, 2020, 60 patients were enrolled. 55 (91.7%) patients completed the full two-cycle treatment successfully. 51 patients underwent surgery and R0 resection was achieved in 50 (98.0%) patients. pCR (ypT0N0) was identified in 20 (39.2%) patients and 5 (9.8%) patients had complete response of the primary tumor but residual disease in lymph nodes alone (ypT0N+). 58 patients (96.7%) had any-grade treatment-related adverse events (TRAEs), with the most common being leukocytopenia (86.7%). 34 patients (56.7%) had adverse events of grade 3 or worse, and one patient (1.7%) occurred a grade 5 adverse event. There was no in-hospital and postoperative 30-day as well as 90-day mortality.

Conclusions: The robust antitumor activity of camrelizumab and chemotherapy was confirmed and demonstrated without unexpected safety signals. Our findings established camrelizumab and chemotherapy as a promising neoadjuvant treatment for locally advanced ESCC.

Trial Registration Number: ChiCTR1900026240.