Anggriyani Wahyu Pinandari

Purpose: In many low- and middle-income countries, access to molecularly targeted therapies for lung cancer remains limited. This study assessed the gap between estimated epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment need and observed uptake in Indonesia and evaluated the gap before and after implementation of the National Reimbursement System (NRS). We hypothesized that many potentially eligible patients in Indonesia would not receive EGFR-TKI therapy, as they ideally should. Methods: We retrospectively analyzed all patient cases of lung cancer registered between 2008 and 2020 at Indonesia's national referral hospital. Patients with a registered diagnosis verified by histopathology or supporting clinical evidence were included. Because patient-level molecular and clinical eligibility data were incomplete, EGFR-TKI eligibility was estimated using a stepwise epidemiologic model. A model-based sensitivity analysis was performed to assess robustness. Observed uptake was compared before and after NRS implementation. Results: A total of 1,426 patients with lung cancer were included; 67.8% were male; the median age was 55 years for men and 53 years for women. Of those with known stage and histology, 93.6% were stage IV; adenocarcinoma accounted for 57.2% of patients with non–small cell lung cancer. Under lower-bound, primary, and upper-bound models, estimated eligible populations were 128 (9.0%), 226 (15.8%), and 378 (26.5%) patients, respectively. Only 41 patients received EGFR-TKIs, corresponding to 32.0%, 18.1%, and 10.8% of the estimated eligible population, respectively. After NRS implementation, uptake increased from 0% to 25.0% of the primary estimate; however, a substantial gap persisted throughout the study period. Conclusion: Despite national reimbursement, EGFR-TKI uptake remained substantially below the estimated need even under the most conservative model. Persistent barriers that span diagnostics, infrastructure, and financing are likely to contribute. Coordinated strategies beyond formulary listings are required to improve access to EGFR-TKI therapy in middle-income settings.