Safety and short-term efficacy of adjuvant nivolumab after neoadjuvant docetaxel, cisplatin, and fluorouracil for locally advanced esophageal squamous cell carcinoma.

Abstract

271 Background: Efficacy and safety of adjuvant nivolumab has been demonstrated in patients with locally advanced esophageal cancer who received neoadjuvant chemoradiotherapy followed by surgery and had residual pathological disease in the CheckMate-577 trial. Although neoadjuvant docetaxel, cisplatin, and fluorouracil (DCF) is the standard neoadjuvant therapy for patients with locally advanced esophageal squamous cell carcinoma (ESCC) in Japan based on the JCOG1109 study, the safety and efficacy of adjuvant nivolumab in this population remains unclear. Here, we report the short-term safety and efficacy of adjuvant nivolumab after neoadjuvant DCF in patients with locally advanced ESCC. Methods: We retrospectively reviewed medical records of patients who received adjuvant nivolumab after neoadjuvant DCF and surgery for locally advanced ESCC from Nov 2021 to Jun 2023 at National Cancer Center Hospital East. Pathological stage was classified by UICC-TNM 8th edition. Adverse events were assessed according to CTCAE v5.0. Disease-free survival (DFS) was calculated by Kaplan-Meier method. Results: The study included a total of 33 patients with a median age of 67 years (range, 56-77), of which 29 patients were male. All patients had residual pathological disease, with ypStage I/II/III/IV of 5/1/16/11 patients. Median time from surgery to the initiation of adjuvant nivolumab was 10.6 weeks (range, 7.1-16.4 weeks). Treatment-related adverse events (TRAEs) occurred in 27 patients (82%), with pruritus (n = 13, 39%), rash (n = 7, 21%), hypothyroidism (n=7, 21%), xerosis (n = 6, 18%), diarrhea (n = 5, 15%), hypopituitarism (n = 5, 15%), pneumonitis (n = 1, 3%), and hepatic dysfunction (n = 1, 3%). Among these TRAEs, one patient developed grade 3 of hepatic dysfunction, which resolved with corticosteroid. TRAEs which led to discontinuation of nivolumab were hepatic dysfunction (n = 1, 3%), diarrhea (n = 1, 3%), and pneumonitis (n = 1, 3%). No treatment-related death was observed. With a median follow-up of 10.3 months, 1-year DFS rate was 63.3% (95% CI, 39.8-79.7%). Among 9 patients who experienced recurrence (locoregional; n = 3, distant; n = 6), 8 patients received subsequent therapy, including systemic chemotherapy (n = 5) and salvage chemoradiotherapy (n = 3). Conclusions: The safety and short-term efficacy of adjuvant nivolumab after neoadjuvant DCF and surgery was comparable to the results of the CheckMate-577 trial. Our study suggests that adjuvant nivolumab might be a possible treatment option in patients with locally advanced ESCC patients with residual pathological disease after neoadjuvant DCF followed by surgery.