First-line sugemalimab with chemotherapy for advanced esophageal squamous cell carcinoma: a randomized phase 3 study.

Although antiprogrammed death 1 antibody plus chemotherapy has recently been approved for first-line esophageal squamous cell carcinoma (ESCC), antiprogrammed death-ligand 1 antibody may offer another combination option in this setting. In this multicenter, randomized, double-blinded phase 3 trial a total of 540 adults (aged 18-75 years) with unresectable, locally advanced, recurrent or metastatic ESCC and who had not received systemic treatment were enrolled. All patients were randomized at 2:1 to receive either sugemalimab (an anti-PD-L1 antibody; 1,200 mg) or placebo every 3 weeks for up to 24 months, plus chemotherapy (cisplatin 80 mg m - 2 on day 1 plus 5-fluorouracil 800 mg m - 2  day -1 on days 1-4) every 3 weeks for up to six cycles. At the prespecified interim analysis this study had met dual primary endpoints. With a median follow-up of 15.2 months, the prolongation of progression-free survival was statistically significant with sugemalimab plus chemotherapy compared with placebo plus chemotherapy (median 6.2 versus 5.4 months, hazard ratio 0.67 (95% confidence interval 0.54-0.82), P = 0.0002) as assessed by blinded independent central review. Overall survival was also superior with sugemalimab chemotherapy (median 15.3 versus 11.5 months, hazard ratio 0.70 (95% confidence interval 0.55-0.90, P = 0.0076). A significantly higher objective response rate (60.1 versus 45.2%) as assessed by blinded independent central review was observed with sugemalimab chemotherapy. The incidence of grade 3 or above treatment-related adverse events (51.3 versus 48.4%) was comparable between the two groups. Sugemalimab plus chemotherapy significantly prolonged progression-free survival and overall survival in treatment-naïve patients with advanced ESCC, with no unexpected safety signal. The ClinicalTrials.gov identifier is NCT04187352 .