Adjuvant nivolumab after chemoradiotherapy and resection for patients with esophageal cancer: A real‐world matched comparison of overall survival

The Checkmate-577 trial showed a significant disease-free and a non-significant overall survival benefit for nivolumab compared to placebo in esophageal or gastroesophageal junction (GEJ) cancer patients with residual disease after neoadjuvant chemoradiotherapy (nCRT) and resection. Real-world overall survival (OS) data has not yet been presented. The aim of this study was to evaluate OS of patients treated with or without adjuvant nivolumab in a nationwide real-world matched comparison.For this study, patients diagnosed with non-metastatic esophageal or GEJ cancer in 2020-2023 who had residual pathological disease after nCRT and resection were selected from the Netherlands Cancer Registry. 333 patients received treatment with adjuvant nivolumab. From the period before the introduction of nivolumab, 486 patients were selected who received nCRT and resection alone. Propensity score trimming and nearest neighbor matching were used to create two well-balanced groups of 311 patients per treatment group. Median follow-up time was 24.4 months and 31.4 months for patients treated with and without adjuvant nivolumab, respectively. The 2-year OS was 66.8% (95% confidence interval [CI]: 61.6%-72.44%) and 58.8% (95% CI: 53.5%-64.5%) for the groups with and without nivolumab, respectively (log-rank p = 0.024), hazard ratio: 0.75, 95% CI: 0.60-0.97 (p = 0.024). In conclusion, this matched real-world study showed an OS in favor of patients treated with nivolumab compared to patients without nivolumab. This represents the first report on a real-world OS benefit in this setting. As follow-up and the number of events are still limited, these analyses should be interpreted with caution and updated in the forthcoming years.