Efficacy and safety of original versus generic erlotinib in non-small cell lung cancer with epidermal growth factor receptor gene mutations in Thailand: a retrospective cohort study
Pharmacy Practice
Abstract
Background: Non-small cell lung cancer (NSCLC) is a major cause of cancer-related mortality, for which mutations in the epidermal growth factor receptor (EGFR) gene are common in Asian populations. Erlotinib, an EGFR tyrosine kinase inhibitor, has been used as the first-line therapy for EGFR-mutated NSCLC. Generic erlotinib has been introduced in Thailand to increase accessibility, but efficacy and safety are major concerns. Objective: This study aimed to compare the efficacy and safety of generic versus originator erlotinib among Thai patients using real-world data from two quaternary hospitals. Methods: A retrospective cohort study collected data from medical record of advanced or metastatic EGFR-mutated NSCLC receiving either generic or originator erlotinib between September 2019 and September 2021 from Maharaj Nakorn Chiang Mai Hospital and Sunpasitthiprasong Hospital, Thailand. Primary outcomes were clinical benefit rate (CBR) at 12 months, progression-free survival (PFS) and treatment-related adverse events. Kaplan-Meier survival curve with log-rank test and the propensity score (PS)-adjusted models were employed to estimate the difference of response rate and safety between the generic vs. the originator erlotinib. Results: One hundred and seven patients were included. CBR at 12 months of the generic vs. originator erlotinib were 75.4 and 74.0% (adjusted HR 1.47 [95%CI 0.45-4.83, p= 0.519]). Median PFS of the generic vs. originator erlotinib were 15.2 months and 18.9 months (adjusted HR 1.98 [95%CI 0.99-3.94, p = 0.053]). The incidence of any adverse events for the generic vs. originator was 21.0 and 36.0% (adjusted OR 0.84 [95%CI 0.26-2.71, p = 0.770]). Most adverse events comprised mild skin toxicity, with no significant difference between the two groups (adjusted OR 1.03 [95%CI 0.31-3.43, p = 0.958]). Conclusions: No significant differences were noted regarding efficacy or safety between generic and originator erlotinib. These findings support the use of generic erlotinib as a cost-effective alternative in Thailand.
Keywords
- Non-Small Cell Lung Cancer (NSCLC)
- Epidermal Growth Factor Receptor Genes (EGFR)
- erlotinib
- generic drugs