OBJECTIVES: Previous model-based studies have demonstrated that pembrolizumab in combination with chemotherapy is a cost-effective treatment for patients with persistent, recurrent, and metastatic cervical cancer (PRMCC) with Combined Positive Score (CPS) ≥ 1 in the United States (US). Recently published modeling results using the interim analysis (22 months follow-up) from the phase III KEYNOTE-826 showed that adding pembrolizumab to standard of care (SoC, chemotherapy) was associated with 1.42 additional quality-adjusted life years (QALY) and $203,460 additional costs, leading to an incremental cost-effectiveness ratio (ICER) of $142,850/QALY. This study expands on this earlier work and investigates the cost-effectiveness using extended follow-up (additional 17 months).

METHODS: The existing three-state model using a state transition structure has been updated with data from final analysis of KEYNOTE-826 trial to investigate the cost-effectiveness of pembrolizumab with SoC versus SoC alone over a lifetime horizon (50 years) from a US payer perspective. All costs have been updated to the current price year (2023) and discounted by 3% per annum. Updating the model with more mature trial data also reduces the uncertainty around the extrapolation of long-term outcomes such as progression-free survival and time to progression.

RESULTS: Using KEYNOTE-826 final analysis data leads to an increase in the incremental life years (undiscounted) and QALYs (discounted, 3% per annum) to 4.70 and 2.26 respectively, further suggesting that pembrolizumab + SoC offers substantial incremental health benefits compared to SoC alone. As time on treatment at the interim assessment was mature, incremental costs have remained consistent, resulting in a new ICER of $94,682/QALY, suggesting pembrolizumab + SoC remains cost-effective at the willingness-to-pay threshold of $150,000/QALY.

CONCLUSIONS: This model-based analysis utilizing more mature data from KEYNOTE-826 strengthens evidence for the cost-effectiveness of pembrolizumab + SoC compared with SoC for treatment of CPS ≥ 1 patients with PRMCC in the US.