PEMBROLIZUMAB ALONE VERSUS CHEMO-IMMUNOTHERAPY IN METASTATIC NSCLC: A 2024 MEDICARE-BASED MARKOV COST-EFFECTIVENESS ANALYSIS
Author(s)
Nikita Nikita, MD, MPH1, Swapnil Sharma, MD, MPH1, Amy L. Shaver, MPH, PharmD, PhD2, Christina Steinbock-Malfer, BS1, Sarah Gordon, MD1, Scott Keith, PhD1, Kuang-Yi Wen, PhD1, Andrew Chapman, DO1, Hoda Badr, PhD1, Grace Lu-Yao, MPH, PhD1;
1Thomas Jefferson University, Philadelphia, PA, USA, 2Thomas Jefferson University, Cambridge, NY, USA
1Thomas Jefferson University, Philadelphia, PA, USA, 2Thomas Jefferson University, Cambridge, NY, USA
OBJECTIVES: Pembrolizumab monotherapy (IO) and pembrolizumab plus platinum-pemetrexed chemotherapy (IO+Chemo) are first-line standards for metastatic non-small cell lung cancer (NSCLC), but their relative value in a contemporary US Medicare setting remains uncertain. Prior trial-consistent cost-effectiveness analyses generally find that chemo-immunotherapy yields additional QALYs over monotherapy at substantial incremental cost, often with high incremental cost-effectiveness ratios (ICERs). This study develops a transparent Markov model as a pre-calibration platform to compare IO versus IO+Chemo using 2024 Medicare facility costs.
METHODS: We constructed a three-state Markov cohort model (progression-free survival [PFS], progressed disease [PD], death) with 3-week cycles, a lifetime horizon (~29 years), and 3% annual discounting for costs and outcomes. Two strategies were modeled: IO, parameterized to KEYNOTE-024, and IO+Chemo, to KEYNOTE-189. Health state utilities were drawn from metastatic NSCLC literature (PFS: 0.72 IO, 0.70 IO+Chemo; PD: 0.50 both). Costs (2024 USD) were derived from Medicare Part B ASP-based payment limits and the 2024 Physician Fee Schedule: pembrolizumab $12,058 per 200-mg dose; incremental chemotherapy drug and infusion costs; PD costs $5,500 per 3-week cycle; end-of-life cost $30,000 per death. We estimated discounted life-years (LYs), QALYs, costs, and ICERs from the Medicare facility perspective.
RESULTS: In the base case, IO yielded 2.73 LYs, 1.62 QALYs, and $419,706 in discounted costs; IO+Chemo yielded 2.31 LYs, 1.35 QALYs, and $391,337. IO was more effective but more costly than IO+Chemo (ΔLY 0.42; ΔQALY 0.26; Δcost $28,369), with an ICER of approximately $108,000/QALY.
CONCLUSIONS: Under cross-trial survival assumptions and 2024 Medicare facility costs, pembrolizumab monotherapy appears cost-effective compared with pembrolizumab-based chemo-immunotherapy at commonly cited US willingness-to-pay thresholds. Although monotherapy is more effective in this model, prior trial-consistent evaluations generally favor IO+chemo in QALYs, highlighting the importance of formally calibrating survival inputs before applying this framework to comparative effectiveness and value assessments in older or real-world NSCLC populations.
METHODS: We constructed a three-state Markov cohort model (progression-free survival [PFS], progressed disease [PD], death) with 3-week cycles, a lifetime horizon (~29 years), and 3% annual discounting for costs and outcomes. Two strategies were modeled: IO, parameterized to KEYNOTE-024, and IO+Chemo, to KEYNOTE-189. Health state utilities were drawn from metastatic NSCLC literature (PFS: 0.72 IO, 0.70 IO+Chemo; PD: 0.50 both). Costs (2024 USD) were derived from Medicare Part B ASP-based payment limits and the 2024 Physician Fee Schedule: pembrolizumab $12,058 per 200-mg dose; incremental chemotherapy drug and infusion costs; PD costs $5,500 per 3-week cycle; end-of-life cost $30,000 per death. We estimated discounted life-years (LYs), QALYs, costs, and ICERs from the Medicare facility perspective.
RESULTS: In the base case, IO yielded 2.73 LYs, 1.62 QALYs, and $419,706 in discounted costs; IO+Chemo yielded 2.31 LYs, 1.35 QALYs, and $391,337. IO was more effective but more costly than IO+Chemo (ΔLY 0.42; ΔQALY 0.26; Δcost $28,369), with an ICER of approximately $108,000/QALY.
CONCLUSIONS: Under cross-trial survival assumptions and 2024 Medicare facility costs, pembrolizumab monotherapy appears cost-effective compared with pembrolizumab-based chemo-immunotherapy at commonly cited US willingness-to-pay thresholds. Although monotherapy is more effective in this model, prior trial-consistent evaluations generally favor IO+chemo in QALYs, highlighting the importance of formally calibrating survival inputs before applying this framework to comparative effectiveness and value assessments in older or real-world NSCLC populations.
Conference/Value in Health Info
2026-05, ISPOR 2026, Philadelphia, PA, USA
Value in Health, Volume 29, Issue S6
Code
EE54
Topic
Economic Evaluation
Disease
SDC: Geriatrics, SDC: Oncology