Neoadjuvant camrelizumab combined with radiotherapy as a chemotherapy-sparing approach for resectable locally advanced esophageal squamous cell carcinoma: a phase II clinical trial (ESOCORT-NIRT)

BACKGROUND: Camrelizumab combined with radiotherapy may offer an effective neoadjuvant option for locally advanced esophageal squamous cell carcinoma while reducing chemotherapy-related toxicity. We assessed the efficacy and safety of this chemotherapy-sparing regimen. METHODS: In this single-arm phase II trial, adults with resectable thoracic esophageal squamous cell carcinoma received camrelizumab 200 mg intravenously every 3 weeks for two cycles, concurrently with radiotherapy to 41.4 Gy in 23 fractions, followed by esophagectomy 4-8 weeks later. The primary endpoint was major pathologic response (≤ 10% residual viable tumor) among patients undergoing resection. Secondary endpoints were R0 resection rate, pathologic complete response, treatment-related adverse events, postoperative complications, and survival outcomes. TRIAL REGISTRATION: ClinicalTrials.gov NCT05176002. RESULTS: Twenty-five patients were enrolled; three did not undergo surgery (one radiographic complete response with refusal of surgery, one disease progression, and one withdrawal). Twenty-two patients (88%) had esophagectomy, all with R0 resection. Major pathologic response occurred in 12 of 22 patients (54.5%), including pathologic complete response in 8 (36.4%). No grade 3 or higher treatment-related adverse events were observed; the most frequent toxicities were low-grade radiation esophagitis, leukopenia, dermatitis, and hypothyroidism. Postoperative complications were low grade. At a median follow-up of 36 months, five recurrences were recorded, with survival comparable to historical standard neoadjuvant cohorts. CONCLUSIONS: Neoadjuvant camrelizumab plus radiotherapy showed low toxicity, pathologic tumor regression, and favorable postoperative outcomes in resectable esophageal squamous cell carcinoma. This chemotherapy-sparing approach may be an alternative for patients who are unsuitable for or intolerant of standard chemotherapy-based neoadjuvant regimens.