Advanced Lung Cancer Patients’ Use of EGFR Tyrosine Kinase Inhibitors and Overall Survival: Real-World Evidence from Quebec, Canada

Abstract

EGFR tyrosine kinase inhibitors (EGFR-TKIs) are breakthrough palliative treatments for advanced lung cancer patients with tumors harboring mutations in the EGFR gene. Using healthcare administrative data, three cohorts were created to describe the use of three EGFR-TKIs that are publicly funded in Quebec for specific indications (i.e., 1st-line gefitinib, 1st-line afatinib, and post-EGFR-TKI osimertinib). The main objective was to compare overall survival (OS) among patients receiving these treatments to those in previous experimental and real-world studies. The patients who received EGFR-TKIs for indications of interest between 1 April 2001, and 31 March 2019 (or 31 March 2020, for post-EGFR-TKI osimertinib) were included to estimate the Kaplan-Meier-based median OS for each cohort. An extensive literature search was conducted to include comparable studies. For the gefitinib 1st-line (n = 457), the afatinib 1st-line (n = 80), and the post-EGFR-TKI osimertinib (n = 119) cohorts, we found a median OS (in months) of 18.9 (95%CI: 16.3–21.9), 26.6 (95%CI: 13.7-NE) and 19.9 (95%CI: 17.4-NE), respectively. Out of the 20 studies that we retained from the literature review and where comparisons were feasible, 17 (85%) had similar OS results, which further confirms the value of these breakthrough therapies in real-world clinical practice.

Inequalities in survival and care across social determinants of health in a cohort of advanced lung cancer patients in Quebec (Canada): A high‐resolution population‐level analysis

“…De‐identified data was accessible through a tripartite agreement between MSSS, RAMQ, and INESSS 33 . INESSS is not responsible for the content of this publication, however, the cohort used in this study is also included in a larger study by INESSS on EGFR‐TKIs in Quebec 22,23 …”

“…Survival time was calculated in months from the date of first gefitinib prescription to either the date of death or March 31, 2020: the administrative censoring time. Previously selected INNs and DINs were used to identify patients who received osimertinib as a second EGFR‐TKI during their follow‐up after receiving gefitinib 22,23 . Medical interventions involving biopsies that occurred between patients' diagnosis date 32 and their first gefitinib treatment were extracted from physician billing and hospitalization databases with expert‐validated billing and intervention codes (Appendix ) 34,35 .…”

“…The dates for the first indication of lung cancer and the initial lung cancer diagnosis were determined based on previously established methods 32 . Patients who filled a prescription for gefitinib at least once between April 1, 2001 and March 31, 2019 were identified in the community pharmacy services database through previously selected international nonproprietary names (INN) and drug identification numbers (DIN) 22,23 . To form cohort 1 for survival analyses and study the use of osimertinib as a second EGFR‐TKI, we identified the line of treatment associated with patients' first gefitinib treatment using a verified algorithm 22,23 and excluded all patients who did not receive gefitinib as a first‐line palliative treatment.…”

“…32 Patients who filled a prescription for gefitinib at least once between April 1, 2001 and March 31, 2019 were identified in the community pharmacy services database through previously selected international nonproprietary names (INN) and drug identification numbers (DIN). 22 , 23 To form cohort 1 for survival analyses and study the use of osimertinib as a second EGFR‐TKI, we identified the line of treatment associated with patients' first gefitinib treatment using a verified algorithm 22 , 23 and excluded all patients who did not receive gefitinib as a first‐line palliative treatment. From this cohort (cohort 1), a separate cohort (cohort 2) was formed to study the time delay from receiving a tumor biopsy (or biopsy‐related intervention) to receiving treatment.…”

“…Decision‐makers in Quebec are increasingly interested in the real‐world effectiveness of breakthrough palliative therapies for advanced lung cancer, like EGFR tyrosine kinase inhibitors (EGFR‐TKI). While the survival of EGFR‐TKI users in Quebec has been investigated, 22,23 inequalities in survival and treatments by patient subgroups remain unknown. Investigating these inequalities in Quebec is relevant, since Quebec accounts for 23% of the Canadian population 24 and about 16% of all Canadian immigrants in Canada 25 .…”