Prospective multicenter study of camrelizumab in real-world settings for asian patients with esophageal squamous cell carcinoma

Background In this study, we aimed to evaluate the real-world efficacy and safety of camrelizumab and identify clinicolaboratory factors that predict treatment outcomes in patients with unresectable advanced, recurrent, or metastatic esophageal squamous cell carcinoma (ESCC) receiving camrelizumab. Methods Herein, 174 patients with unresectable advanced, recurrent, or metastatic ESCC treated with camrelizumab monotherapy (n = 30), camrelizumab + chemotherapy (CT; n = 91), and camrelizumab + radiotherapy (RT; n = 53) between October 1, 2019 and October 1, 2022 were included. Results The median follow-up time was 20 months (range, 1-34 months). The median progression-free survival (PFS) and overall survival (OS) of the whole cohort were 8 months [95% confidence interval (CI), 6.5-9.5 months] and 14 months (95% CI, 11.2-16.8 months), respectively. After multivariate analysis, receiving > 4 cycles of camrelizumab was identified as an independent predictor of better PFS [hazard ratio (HR), 0.56; 95% CI, 0.38-0.827; P = 0.004] and OS (HR, 0.532; 95% CI, 0.341-0.83; P = 0.005). An intermediate-to-poor lung immune prognostic index (LIPI) was identified as an independent predictor of worse PFS (HR, 1.505; 95% CI, 1.032-2.196; P = 0.034) and OS (HR, 1.657; 95% CI, 1.094-2.51; P = 0.017). The disease control rate of patients in the camrelizumab monotherapy group, camrelizumab + CT group, and camrelizumab + RT group was 92.3% (95% CI, 74.9-99.1%), 90.6% (95% CI, 82.3-95.9%), and 96.1% (95% CI, 86.8-99.5%), respectively. The treatment-related adverse events (AEs) of grade 3 or higher were reported in 67 patients (38.5%). The most common treatment-related AEs were decreased neutrophil count (23.0%), decreased white blood cell count (19.5%), anemia (7.5%), and pneumonitis (4.6%). One patient (0.6%) died from a treatment-related AE of immune checkpoint inhibitor-induced myocarditis. Conclusion Camrelizumab was safe and effective as both monotherapy and part of a combination therapy. Longer PFS and OS were associated with receiving > 4 cycles of camrelizumab and having a good LIPI. LIPI can be used as a prognostic biomarker for ESCC patients receiving camrelizumab + RT.