Background
Recent advances in cervical cancer treatment have expanded options for patients with locally advanced disease. In January 2024, the U.S. Food and Drug Administration approved pembrolizumab, a PD-1 immune checkpoint inhibitor, to be used together with chemoradiotherapy (CRT) for patients with FIGO 2014 stage III-IVA cervical cancer. This approval was based on evidence that adding pembrolizumab can improve outcomes beyond standard CRT alone.
Cervical cancer at stage III-IVA is considered locally advanced and often requires aggressive combined treatment. Standard CRT includes external-beam radiation, brachytherapy, and platinum-based chemotherapy. Although this approach can be curative for some patients, recurrence remains a concern, and new therapies may improve long-term survival. Because pembrolizumab is a high-cost biologic therapy, its real-world value depends not only on clinical benefit but also on whether the added outcomes justify the additional expense.
This study examined the cost-effectiveness of pembrolizumab plus CRT compared with CRT alone from the perspective of a U.S. payer. In practical terms, the analysis asked whether the extra survival and quality-of-life benefits are worth the added cost in the American health care system.
How the study was done
The investigators built a state-transition cohort model, a type of economic model that follows a group of patients over time as they move through different health states. The model included four states: progression-free, first progression, second progression, and death. This structure allowed the researchers to estimate how long patients remained without disease worsening, how often the cancer returned or advanced, and how long they survived overall.
Transition probabilities were based on patient-level data from the final analysis of the KEYNOTE-A18 trial, which compared pembrolizumab plus CRT with CRT alone. Rather than using only short-term trial results, the team applied parametric survival modeling to project outcomes over a patient’s lifetime. This is important because cost-effectiveness studies need long-term estimates, while clinical trials usually follow patients for a limited period.
For health states after the first progression, the researchers adjusted projections according to expected pembrolizumab use in recurrent or metastatic cervical cancer in U.S. practice. This helped make the model more reflective of how patients are actually treated after their disease progresses.
The analysis also incorporated adverse event rates and utility values from KEYNOTE-A18. Utility values are numerical estimates of quality of life, with 1 representing perfect health and 0 representing death. Costs were taken from Analysource, national statistics, and published literature. The model discounted costs and health outcomes at 3% per year, which is standard in U.S. health economic evaluations because future costs and benefits are generally valued slightly less than immediate ones.
To test robustness, the authors performed deterministic sensitivity analysis, which changes one input at a time to see how much the results shift, and probabilistic sensitivity analysis, which varies all inputs together across many simulated scenarios. These methods help show whether the findings remain stable despite uncertainty in the data.
Key findings
The model projected that patients receiving pembrolizumab plus CRT would gain 1.87 additional life years and 1.60 additional quality-adjusted life years, or QALYs, compared with CRT alone. These gains suggest not only longer survival but also better quality of life during that survival.
However, those benefits came with higher costs. The incremental cost of pembrolizumab plus CRT was estimated at $157,681 per patient relative to CRT alone. When this added cost was divided by the additional QALYs gained, the incremental cost-effectiveness ratio, or ICER, was $98,292 per QALY.
In U.S. health economics, an ICER below commonly used willingness-to-pay thresholds is often considered cost-effective. Many analyses in the United States reference thresholds of $100,000 to $150,000 per QALY, depending on the context. In this study, the ICER fell below the $150,000/QALY threshold, suggesting that pembrolizumab plus CRT provides reasonable value for money under that benchmark.
The probabilistic sensitivity analysis showed that pembrolizumab plus CRT had a 90% chance of being cost-effective at a willingness-to-pay threshold of $150,000/QALY. This high probability strengthens confidence in the conclusion, even when accounting for uncertainty in costs, survival estimates, and quality-of-life inputs.
What the results mean
The findings suggest that pembrolizumab adds meaningful clinical value for women with FIGO 2014 stage III-IVA cervical cancer in the United States. The treatment appears to extend life and improve quality-adjusted survival enough to justify its additional cost at a willingness-to-pay threshold of $150,000 per QALY.
From a broader perspective, this study supports the use of immunotherapy earlier in the treatment course for locally advanced cervical cancer. Pembrolizumab is not a replacement for chemoradiotherapy; rather, it enhances the standard regimen by helping the immune system recognize and attack cancer cells more effectively. For patients facing a high-risk diagnosis, even modest improvements in progression-free and overall survival can be clinically important.
That said, cost-effectiveness does not mean the treatment is inexpensive or universally affordable. The analysis shows that the regimen is likely to be considered good value within the U.S. payer system, but actual access can still depend on insurance coverage, copay support, and institutional policies.
Clinical context
Cervical cancer remains a significant cause of cancer-related illness in women worldwide, though screening and vaccination have reduced incidence in many regions. For stage III-IVA disease, outcomes are strongly influenced by tumor burden, local extension, nodal involvement, and response to radiation-based treatment. The addition of an immune checkpoint inhibitor is part of a larger trend toward integrating immunotherapy into gynecologic oncology.
Pembrolizumab blocks the PD-1 pathway, which cancer cells can use to evade immune detection. By inhibiting this pathway, the drug may restore immune activity against the tumor. While this mechanism has shown promise across multiple cancers, the price of immunotherapy often raises important questions about affordability and access. Studies like this one are essential because they help clinicians, payers, and policymakers weigh value alongside efficacy.
Limitations
As with any economic model, the results depend on assumptions and available data. The projections beyond the duration of the KEYNOTE-A18 trial relied on statistical modeling, which introduces uncertainty. Real-world outcomes may differ from trial-based estimates, especially when treatment adherence, comorbidities, and practice patterns vary.
In addition, cost estimates can change over time due to drug pricing, reimbursement policy, and the availability of generics or biosimilars for parts of the regimen. The analysis also reflects the U.S. payer perspective, so the results may not directly apply to other countries with different health systems and drug pricing structures.
Another important point is that the cost-effectiveness conclusion is tied to the willingness-to-pay threshold used. At a lower threshold, the treatment might not appear cost-effective. Therefore, while the findings are encouraging, they should be interpreted in the context of local budgets and health policy priorities.
Conclusion
In this U.S.-based cost-effectiveness analysis, pembrolizumab plus chemoradiotherapy for FIGO 2014 stage III-IVA cervical cancer improved life expectancy and quality-adjusted survival at an incremental cost that produced an ICER of $98,292 per QALY. The regimen was projected to be cost-effective at a willingness-to-pay threshold of $150,000 per QALY.
Overall, the study supports pembrolizumab plus CRT as a clinically meaningful and economically reasonable addition to standard care for patients with locally advanced cervical cancer in the United States. As immunotherapy continues to move into earlier stages of cancer treatment, evidence on both effectiveness and value will remain crucial for guiding practice and policy.
