Cost-effectiveness of Adjuvant Pembrolizumab after Nephrectomy for High-risk Renal Cell Carcinoma: Insights for Patient Selection from a Markov Model

Purpose:The KEYNOTE-564 trial demonstrated that adjuvant pembrolizumab after nephrectomy for clear cell renal cell carcinoma decreased the risk of disease progression and potentially overall mortality as well. Herein, we used a Markov model to weigh the costs, toxicities, and efficacy of pembrolizumab to further investigate its utility.Materials and Methods:Decision-analytic Markov modeling was used to conduct a cost-utility analysis of adjuvant pembrolizumab versus observation after nephrectomy for high-risk clear cell renal cell carcinoma, using data from KEYNOTE-564 to inform model probabilities. Primary outcomes were quality-adjusted life years, Medicare costs, and incremental cost-effectiveness ratios. The willingness-to-pay threshold utilized was $100,000/quality-adjusted life year.Results:At 5 years, adjuvant treatment with pembrolizumab resulted in 0.3 additional quality-adjusted life years at an additional cost of $99,484 relative to observation. Pembrolizumab was found not to be cost-effective at a 5-year time horizon (incremental cost-effectiveness ratio=$326,534). On sensitivity analysis, pembrolizumab became cost-effective if its per cycle cost was <$5,064 (base=$10,278) or its 5-year progression benefit was >18.8% (base 9%). Upon simulation, pembrolizumab was cost-effective for 29% of patients at 5 years. Specifically, we found that pembrolizumab would be cost-effective at 5 years for patients with at least a 59% 5 year risk of progression, which corresponds to a Mayo Progression-free Survival Score ≥10.Conclusions:At current prices, adjuvant pembrolizumab was found to be cost-effective only for the highest risk subset of clear cell renal cell carcinoma patients 5 years after treatment, including patients with complete metastasectomy, regional lymph node involvement, or ≥7cm pT3 tumors with sarcomatoid features. Longer-term trial data, including overall survival results, are necessary to confirm these extrapolations.