It remains unclear whether adding CTLA-4 blockade to PD-1/PD-L1 blockade improves clinical outcomes in cervical cancer (CC). In this randomized, double-blind, placebo-controlled, phase 2 study (ClinicalTrials.gov: NCT04590599), patients with recurrent/metastatic CC (R/M CC) who experienced disease progression after or during platinum-based chemotherapy were enrolled from 37 centers across China and randomly assigned (1:1), stratified by PD-L1 expression and prior treatment lines, to receive either IBI310 plus sintilimab or placebo plus sintilimab intravenously every 3weeks for 12weeks, followed by sintilimab alone. The primary endpoint was the objective response rate (ORR). Pivotal secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety. 205 patients were randomized to receive IBI310-sintilimab (n= 103) or placebo-sintilimab (n= 102). The ORR difference between the IBI310-sintilimab arm (32.3%, 95% confidence interval [CI]: 23.3%-42.5%) and the placebo-sintilimab arm (23.5%, 95% CI: 15.5%-33.1%) was not significant (p= 0.17). IBI310-sintilimab and placebo-sintilimab exhibited median PFS values of 3.6 (95% CI: 2.7-6.3) and 4.2months (95% CI: 2.8-6.2), respectively (hazard ratio [HR]= 0.91, 95% CI: 0.65-1.27; p= 0.58). The median OSs were 13.9months (95% CI: 11.5-25.6) in the IBI310-sintilimab arm and 17.2months (95% CI: 13.7-25.9) in the placebo-sintilimab arm (HR= 1.12, 95% CI: 0.79-1.58; p= 0.54). Adding IBI310 to sintilimab increased the incidence of grade ≥3 treatment-related adverse events (55% versus 19%). Compared to single-agent PD-1/PD-L1 blockade, dual blockade of CTLA-4 and PD-1/PD-L1 did not significantly improve clinical outcomes in R/M CC. This work was funded by Innovent Biologics (Suzhou).
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