Safety and efficacy of camrelizumab combined with radiotherapy as neoadjuvant therapy for locally advanced esophageal squamous cell carcinoma: A prospective single-arm phase II clinical trial.

4057 Background: Neoadjuvant chemoradiotherapy followed by esophagectomy is the standard of care for locally advanced esophageal squamous cell carcinoma (ESCC). However, approximately 30% of patients still develop distant metastases and have a high incidence of treatment-related adverse events. Immunotherapy, as a new modality for anti-cancer treatment, has shown promising clinical benefits for patients with ESCC. The synergistic effects of immunotherapy and radiotherapy make their combination promising as neoadjuvant treatment for locally advanced ESCC. Methods: All participants who meet the inclusion criteria will be enrolled after signing the informed consent form. Patients with thoracic segment esophageal cancer with clinical stage T2-3 N0 M0 or T2-3 N+ M0 will be included. They will be treated with radical surgery within 4–8 weeks after the completion of two cycles of neoadjuvant radiotherapy in combination with camrelizumab according to the study schedule. The primary endpoint is the major pathological remission rate of all per-protocol patients. The secondary endpoints are the R0 resection rate, pathological complete remission rate, and adverse events. The interim analysis will be conducted after half of the planned number of patients have been enrolled. The trials will be terminated when more than two treatment-related deaths occur or fewer than five patients have major pathological remission. Results: A total of 25 patients were enrolled, 3 patients did not undergo surgery, of which 1 had imaging CR after neoadjuvant therapy and refused surgical treatment; 1 progressed during neoadjuvant therapy, and the other had immune pneumonitis and renal insufficiency during neoadjuvant therapy. The final results of the study noted that of the 22 patients who underwent surgery. Twelve of 22 (54.5%) patients had a pathologic response, all consisting of an MPR with ≤10% RVT, including 8 of 22 (36.4%) pathologic complete responses. Conclusions: The NRIT regimen is safe and feasible for patients with ESCC. Clinical trial information: NCT05176002 .