Abstract
PURPOSE: Recurrent or metastatic cervical cancer (R/M CC) has limited therapeutic options after first-line treatment failure. Both enlonstobart and camrelizumab are anti-PD-1 antibodies recommended for second-line treatment, but direct comparative evidence is lacking. This study aimed to evaluate the relative efficacy of enlonstobart versus camrelizumab as second-line treatments in patients with R/M CC. METHODS: We conducted an unanchored matched-adjusted indirect comparison (MAIC) using individual patient data from the single-arm enlonstobart Phase II trial and published aggregate data from the camrelizumab phase II trial, both of which targeted an R/M CC population with prior platinum-based treatment failure. Entropy balancing was used to adjust for eight baseline covariates. Primary endpoints were overall survival (OS) and progression-free survival (PFS). Cox proportional hazards models were used to estimate hazard ratios (HRs) for the survival endpoints. A simulated treatment comparison (STC) was performed as sensitivity analysis. RESULTS: Before adjustment, no significant differences were observed between treatments for OS or PFS. After MAIC adjustment, enlonstobart demonstrated significant OS advantage over camrelizumab (HR=0.51, 95% CI 0.27-0.94, p=0.03), with median OS of 32.2 versus 14.94 months. PFS showed a favorable trend but was not statistically significant (HR=0.69, 95% CI 0.42-1.14, p=0.15). STC analysis corroborated the OS benefit and suggested significant PFS advantage of enlonstobart over camrelizumab. Safety profiles were comparable between treatments. CONCLUSION: This indirect comparison demonstrated that enlonstobart provided a significant OS advantage compared to camrelizumab in patients with second-line R/M CC. These findings suggest enlonstobart may represent a promising therapeutic option for PD-(L)1 positive R/M CC patients.