Cost Effectiveness of Pembrolizumab in Combination with Chemotherapy for the Treatment of Patients with Locally Advanced or Metastatic HER2-Negative Gastric or Gastroesophageal Cancer in Mexico
Author(s)
Monica M. Rojas, MD, PhD1, Daniela Medrano, QFB2, Roberto Acevedo, MS2, Victoria Wurcel, MASc, MSc, MD3, Shalini Kumari, MSc4, Tanya Ahuja, MA4, Srishti Mehta, MA4, Asmita Gakhar, MSc4, Adriana Valderrama, MBA, PhD5, Kate Young, MPH, PhD5;
1MSD Colombia, Bogotá, Colombia, 2MSD Mexico, Ciudad de México, Mexico, 3MSD Argentina, Buenos Aires, Argentina, 4CHEORS, North Wales, PA, USA, 5Merck & Co., Inc., Rahway, NJ, USA
1MSD Colombia, Bogotá, Colombia, 2MSD Mexico, Ciudad de México, Mexico, 3MSD Argentina, Buenos Aires, Argentina, 4CHEORS, North Wales, PA, USA, 5Merck & Co., Inc., Rahway, NJ, USA
OBJECTIVES: This study evaluated the cost effectiveness of pembrolizumab in combination with chemotherapy for the treatment of patients with locally advanced unresectable or metastatic HER2-negative gastric or GEJ adenocarcinoma in Mexico from the public payer´s perspective.
METHODS: A three-health state partitioned survival model was developed to project health outcomes for patients using data from the KEYNOTE-859 trial. The health states were progression-free (PF), progressed disease (PD), or death. Costs and outcomes were calculated over a time horizon of 5 years for the base case analysis. The costs in Mexican pesos included drug acquisition, drug administration, adverse event, subsequent treatment, disease management, progression cost, and end-of-life. An annual discount rate of 5% was applied to costs, life years (LYs) and quality adjusted life years (QALYs) as per the “Consejo General de Salud” guidelines. The model estimated total LYs, QALYs, and costs for a treated patient as well as by health state (PF and PD). Utility inputs were derived from the EQ-5D-5L data collected in KEYNOTE-859 using Mexican algorithm. Alternate scenarios were tested in the sensitivity analyses.
RESULTS: Over a 5-years’ time horizon, in the overall population, pembrolizumab + chemotherapy was estimated to provide an incremental QALY gain of 0.028 QALYs per patient with LY gain of 0.029 LY per patient and a cost reduction of MXN$104,656 compared to nivolumab + chemotherapy. The scenario analysis revealed that the model was most sensitive to the treatment duration hazard ratio of nivolumab + doublet chemotherapy versus pembrolizumab + chemotherapy.
CONCLUSIONS: This analysis demonstrated that pembrolizumab combined with chemotherapy was the dominant strategy. Over a five-year horizon, this combination not only yields higher QALYs but also results in cost savings compared to nivolumab with doublet chemotherapy for patients with locally advanced or metastatic HER2-negative gastric or GEJ adenocarcinoma in Mexico's healthcare system.
METHODS: A three-health state partitioned survival model was developed to project health outcomes for patients using data from the KEYNOTE-859 trial. The health states were progression-free (PF), progressed disease (PD), or death. Costs and outcomes were calculated over a time horizon of 5 years for the base case analysis. The costs in Mexican pesos included drug acquisition, drug administration, adverse event, subsequent treatment, disease management, progression cost, and end-of-life. An annual discount rate of 5% was applied to costs, life years (LYs) and quality adjusted life years (QALYs) as per the “Consejo General de Salud” guidelines. The model estimated total LYs, QALYs, and costs for a treated patient as well as by health state (PF and PD). Utility inputs were derived from the EQ-5D-5L data collected in KEYNOTE-859 using Mexican algorithm. Alternate scenarios were tested in the sensitivity analyses.
RESULTS: Over a 5-years’ time horizon, in the overall population, pembrolizumab + chemotherapy was estimated to provide an incremental QALY gain of 0.028 QALYs per patient with LY gain of 0.029 LY per patient and a cost reduction of MXN$104,656 compared to nivolumab + chemotherapy. The scenario analysis revealed that the model was most sensitive to the treatment duration hazard ratio of nivolumab + doublet chemotherapy versus pembrolizumab + chemotherapy.
CONCLUSIONS: This analysis demonstrated that pembrolizumab combined with chemotherapy was the dominant strategy. Over a five-year horizon, this combination not only yields higher QALYs but also results in cost savings compared to nivolumab with doublet chemotherapy for patients with locally advanced or metastatic HER2-negative gastric or GEJ adenocarcinoma in Mexico's healthcare system.
Conference/Value in Health Info
2025-05, ISPOR 2025, Montréal, Quebec, CA
Value in Health, Volume 28, Issue S1
Code
EE287
Topic
Economic Evaluation
Disease
SDC: Oncology