Neoadjuvant serplulimab combined with chemotherapy for resectable oesophageal squamous cell carcinoma: a single-arm, phase 2 trial

In this phase 2 trial, patients diagnosed with locally advanced oesophageal squamous cell carcinoma underwent three cycles of neoadjuvant therapy comprising serplulimab, carboplatin, and albumin paclitaxel. The primary endpoint was the pathological complete response assessed by two independent pathologists and was defined as no residual viable tumours at both the primary tumour site and all the lymph nodes. The secondary endpoints included adverse events and overall survival time. In total, 85.4% of patients experienced adverse events of any grade, and 4.2% reported Grade 3 adverse events; 45 patients underwent pathological evaluation, 14 (31.1%, 95% confidence interval, 18.2-46.6%) achieved pathological complete response, and the two-year survival rate was 88.3%. Imaging mass cytometry revealed that patients without pathological complete response presented immunosuppressive molecule expression, and expanded immunosuppressive fibroblast neighbourhoods. Here we show, serplulimab and chemotherapy are associated with modest antitumour activity and a tolerable safety profile in patients with locally advanced oesophageal squamous cell carcinoma. A phase 3 randomised trial featuring continued follow-up is essential for a formal evaluation. ClinicalTrials.gov identifier: NCT05659251.