Abstract 428P
Background
Second-line immune checkpoint inhibitors (2L-ICIs) improve the survival of advanced non-small cell lung cancer (NSCLC) patients compared with chemotherapy (CT). However, 2L-ICIs are more expensive than CT. Thus, 2L-ICIs are not reimbursable in many countries, including Thailand. Most economic studies on 2L-ICIs derived the treatment efficacy from randomized controlled trials, which may not reflect the real-world effectiveness; moreover, evidence from low- to middle-income countries is scarce. Thus, we aimed to evaluate the cost-effectiveness of 2L-ICIs using real-world evidence.
Methods
Medical records of patients with advanced NSCLC receiving 2L-ICI or CT at Siriraj Hospital, Bangkok, Thailand from 2016 to May 2023 were reviewed to evaluate treatment effectiveness and direct medical costs. Patients receiving treatment from July 2023 to March 2024 were interviewed to determine utility and direct nonmedical costs. A Markov model was used to analyze the lifetime costs and health outcomes from societal perspective. One-way and probabilistic sensitivity analyses and scenario analyses were performed.
Results
Data were collected from 209 patients (72 and 137 patients received 2L-ICI and CT, respectively). The 2L-ICIs significantly improved overall survival (hazard ratio 0.64, 95% confidence interval 0.47–0.89, p=0.008) and increased the quality-adjusted life years (QALYs) from 0.54 to 1.11, resulting in QALY gain of 0.57; lifetime cost increased from 17,204 USD to 34,424 USD. The incremental cost-effectiveness ratio (ICER) of 2L-ICI was 30,104 USD/QALY. Scenario analysis revealed that 2L-ICIs were more cost effective than CT for healthier patients (ECOG 0–1) with ICER of 9,856 USD/QALY. Considering Thailand’s willingness-topay threshold of 4,444 USD/QALY, 2L-ICIs could be cost effective if the cost of atezolizumab was reduced by 86%.
Conclusions
Real-world evidence confirmed the effectiveness of 2L-ICIs in improving the survival of advanced NSCLC patients compared with CT. However, 2L-ICIs are not cost effective for patients with advanced NSCLC in Thailand. Drug price negotiation and patient subgroup prioritization would help make second-line ICIs more accessible.
Legal entity responsible for the study
Faculty of Medicine Siriraj Hospital, Mahidol University.
Funding
Faculty of Medicine Siriraj Hospital, Mahidol University.
Disclosure
All authors have declared no conflicts of interest.