Pathological complete response after neoadjuvant chemoimmunotherapy with toripalimab or camrelizumab in esophageal squamous cell carcinoma: A systematic review and meta-analysis.

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Background: Neoadjuvant chemoimmunotherapy has reshaped the treatment paradigm for esophageal squamous cell carcinoma (ESCC), yet the relative efficacy of individual PD-1 inhibitors remains undefined. Pathological complete response (pCR) is a validated surrogate for long-term survival in ESCC. We performed a systematic review and indirect comparative synthesis to evaluate pCR outcomes between toripalimab and camrelizumab based neoadjuvant regimens. Methods: A systematic literature search of PubMed and Google Scholar was performed for studies published from January 2021 through January 2026. Identified prospective and observational studies evaluating toripalimab or camrelizumab combined with platinum-based chemotherapy in resectable ESCC. Dual independent screening and extraction were performed. Study quality was assessed using the Newcastle–Ottawa Scale and Jadad score. Case reports and animal studies were excluded. Pooled pCR event rates were calculated using random-effects modeling. Indirect comparisons were interpreted descriptively. Results: Thirteen studies comprising 916 patients were included: 3 randomized controlled trials, 4 single-arm trials, 1 cohort study, and 5 observational studies. Five studies evaluated toripalimab-based regimens (n = 461) and eight evaluated camrelizumab-based regimens (n = 6 72). In single-arm neoadjuvant chemoimmunotherapy studies, pooled pCR was 35% for camrelizumab (RD 0.35, 95% CI 0.30–0.40, I²=39%; 8 studies, n=672) and 30% for toripalimab (RD 0.30, 95% CI 0.26–0.35, I²=0%; 5 studies, n=461). These pooled estimates represent event rates and should be interpreted as an indirect comparison. Conclusions: Neoadjuvant chemoimmunotherapy incorporating camrelizumab demonstrated a numerically higher pooled pathological complete response rate than toripalimab in resectable ESCC (35% vs 30%); however, these findings derive from indirect cross-trial comparisons and remain vulnerable to heterogeneity in staging, chemotherapy backbone, surgical selection, and pCR assessment. Prospective head-to-head randomized trials with survival endpoints are required to determine whether this pCR signal translates into meaningful improvements in disease-free and overall survival.