Real-world efficacy and safety profile of low-dose cadonilimab in recurrent or metastatic cervical cancer as first-line therapy.

Background: Cadonilimab, a bispecific PD-1/CTLA-4 antibody, has activity in recurrent/metastatic cervical cancer (R/M CC), but high costs limit accessibility, especially in low- and middle-income countries. Hence, we aimed to assess whether lower dose of cadonilimab may achieve comparable clinical outcomes with improved tolerability. Methods: This retrospective real-world study evaluated 137 R/M CC patients treated with cadonilimab 6mg/kg every three weeks as first-line therapy at Sichuan Cancer center from January 1, 2023, to September 30, 2025. The primary endpoint was the objective response rate (ORR). Secondary endpoints included the disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety. Results: Among 133 efficacy-evaluable patients, the ORR was 55.6%, consisting of complete and partial responses in 10.5% and 45.1% of patients, respectively. The DCR was 83.5%. In patients aged ≥65 years, the ORR and DCR were 47.8% and 87.0%, respectively. The 12-month OS rate was 92.1% (95% CI, 86.5%-98.0%), and the 12-month PFS rate was 67.3% (95% CI, 58.4%-77.4%). Grade ≥3 treatment-related adverse events occurred in 78.8% and the most common were neutropenia, anemia, and lymphopenia. While immune-related adverse events were observed in 35.0% of patients, severe events were rare, occurring in only 3.6%. Furthermore, clinical outcomes and safety profiles were comparable across different chemotherapy regimens. Conclusions: Low-dose cadonilimab demonstrates robust efficacy and manageable safety in R/M CC, with encouraging outcomes in elderly patients. Prospective randomized trials are needed to validate the efficacy of dose-reduced strategies.