Prospective Observational Study of Cadonilimab in Cervical Cancer: Real-World Efficacy, Safety, and Predictive Biomarkers

Objective Immune checkpoint inhibitors (ICIs) have emerged as a promising treatment option for cervical cancer in clinical trials. This interim analysis of an ongoing prospective cohort study evaluates the real-world efficacy of cadonilimab, a bispecific antibody targeting PD-1 and CTLA-4, and identifies early prognostic biomarkers in cervical cancer patients. Methods This preliminary report analyzes the first 51 consecutive patients from a protocol-driven observational cohort initiating cadonilimab (≥2 cycles) between June 2022 and August 2025. Standardized prospective data collection included clinicopathological variables, peripheral blood biomarkers, and protocol-defined tumor assessments (RECIST v1.1 every 6 weeks). Interim efficacy endpoints (objective response rate [ORR], disease control rate [DCR], 3-month progression-free survival [PFS] rate) and safety (CTCAE v5.0) were evaluated, with multivariate analyses to identify predictive factors. Interim Results At the data cutoff date (August 2025), the cohort demonstrated an ORR of 72.5% and a DCR of 90.2%. The 3-month PFS rate was 80.9% (95% CI: 69.7-93.8). The median progression-free survival (mPFS) and median overall survival (mOS) were not reached. Multivariable analysis revealed that squamous cell carcinoma histology and baseline IL-6 levels ≤5.4 pg/mL (p<0.05) were significantly associated with higher ORR. Most adverse events (AEs) were manageable, with hematologic toxicities (e.g., anemia, leukopenia) being the most frequently observed. Notably, patients with baseline complement C3 levels <0.90 g/L exhibited a higher incidence of AEs. Conclusions This interim analysis suggests cadonilimab's favorable benefit-risk profile in cervical cancer, with early biomarker trends requiring validation in the final cohort. Continued follow-up will clarify long-term outcomes and biomarker robustness.