Deleterious association between proton pump inhibitor and protein kinase inhibitor exposure and survival for patients with lung cancer: A nationwide cohort study.

Introduction: Previous studies have identified an interaction between protein kinase inhibitors (PKIs) and proton pump inhibitors (PPIs) in patients with lung cancer. This type of interaction may reduce the efficacy of PKIs. However, the effect of PKI-PPI interaction on patient mortality remains controversial. This study set out to determine the impact of PKI-PPI interaction on overall survival for lung cancer patients.

Materials And Methods: This study was conducted using data from the French National Health Care Database from January 1, 2011 to December 31, 2021. We identified patients with: (i) an age equal to or greater than 18 years; (ii) lung cancer; and (iii) at least one reimbursement for one of the following drugs: erlotinib, gefitinib, afatinib and osimertinib. Patients were followed-up between the first date of PKI reimbursement and either December 31, 2021 or if they died, the date on which death occurred. The cumulative exposure to PPI duration during PKI treatment was calculated as the ratio between the number of concomitant exposure days to PKI and PPI and the number of exposure days to PKI. A survival analysis using a Cox proportional hazards model was then performed to assess the risk of death following exposure to a PKI-PPI interaction.

Results: 34,048 patients received at least one reimbursement for PKIs of interest in our study: 26,133 (76.8 %) were exposed to erlotinib; 3,142 (9.2 %) to gefitinib; 1,417 (4.2 %) to afatinib; and 3,356 (9.9 %) to osimertinib. Patients with concomitant exposure to PKI-PPI interaction during 20 % or more of the PKI treatment period demonstrated an increased risk of death (HR, 1.60 [95 % CI, 1.57-1.64]) compared to other patients. When this cut-off varied from 10 % to 80 %, the estimated HR ranged from 1.46 [95 % CI, 1.43-1.50] to 2.19 [95 % CI, 2.12-2.25].

Discussion/conclusion: In our study, an elevated risk of death was observed in patients exposed to PKI-PPI interaction. Finally, we were able to identify a dose-dependent effect for this interaction. This deleterious effect of osimertinib and PPI was revealed for the first time in real life conditions.