Search

Introduction: Although osimertinib is a standard first-line treatment for patients with advanced-stage non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations, the incidence rate of pneumonitis associated with osimertinib is high. However, there are few reports about the safety and efficacy of osimertinib rechallenge after the development of pneumonitis., Methods: We conducted a retrospective multicentre cohort study of consecutive patients who developed pneumonitis associated with osimertinib as a first-line and received osimertinib rechallenge. The primary outcome was the incidence rate of any grade pneumonitis after osimertinib rechallenge. The secondary outcome was treatment efficacy in patients after osimertinib rechallenge., Results: In total, 33 patients who received osimertinib rechallenge were included. Of them, 26 patients had grade 1, 6 patients had grade 2, and 1 patient had grade 3 initial pneumonitis. The median follow-up period after the osimertinib rechallenge was 16.9 months (interquartile range, 11.1-21.3 months). After the start of osimertinib rechallenge, five patients (15%) experienced mild relapsed pneumonitis. Three of the five patients had similar imaging patterns for initial and relapsed pneumonitis. No significant differences in characteristics were observed between patients with and without relapsed pneumonitis. The median progression-free survival after osimertinib rechallenge was not achieved (95% confidence interval: 10.3 months - not reached)., Conclusion: Osimertinib rechallenge was feasible and effective for patients who developed initial pneumonitis associated with first-line osimertinib therapy. Osimertinib might be considered a treatment option even after the development of mild initial pneumonitis., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Purpose: This study aimed to determine the incidence and clinical course of epidermal growth factor receptor (EGFR)-mutated lung cancer with histologic transformation (HT)., Patients and Methods: We conducted a multicentre, retrospective, cohort study of patients with advanced EGFR-mutated lung cancer who received EGFR-tyrosine kinase inhibitors (TKIs) between 2012 and 2019. The primary outcome was the incidence of HT. The secondary outcome was treatment efficacy in patients with HT., Results: In total, 6356 patients were enrolled. In 2624 patients, the histological type was proven by rebiopsy after acquiring resistance to EGFR-TKIs. Among them, 74 patients had HT (incidence rate: 2.8% [95% confidence interval: 2.3%-3.5%]). The median progression-free survival after EGFR-TKIs and first-line therapy after confirming HT was 10.4 and 4.4 months, respectively, which was not significantly different between patients with transformation to high-grade neuroendocrine carcinoma and those with transformation to another subtype of non-small cell lung cancer. Overall survival after confirming HT was 12.2 months. Twenty-seven patients received immune checkpoint inhibitors: 6 and 21 received immune checkpoint inhibitors before and after confirming HT, respectively. No patients achieved 1-year progression-free survival. The median progression-free survival after immune checkpoint inhibitor therapy after confirming HT was 1.6 months., Conclusion: HT occurred in approximately 3% of EGFR-mutated patients who developed resistance to EGFR-TKIs. Cytotoxic agents are likely to be effective in patients with HT. However, the therapeutic effectiveness of immune checkpoint inhibitors was limited in these patients. Given the rarity of HT and absence of prospective trials, our findings are important to inform the treatment of these patients., (Copyright © 2022 Elsevier Ltd. All rights reserved.)