Treatment Patterns and Resource Use After Osimertinib Discontinuation in Patients with EGFR + Metastatic NSCLC

Abstract Introduction Current treatment guidelines for patients with epidermal growth factor receptor (EGFR)-mutated metastatic non-small cell lung cancer (mNSCLC) recommend EGFR tyrosine kinase inhibitors (TKIs) as the standard of care for first-line treatment, with third-generation osimertinib the preferred choice. However, most patients develop resistance to targeted therapy, and subsequent systemic chemotherapy is recommended. The aim of this study was to characterize the subsequent line of therapy (LOT) following osimertinib in patients with EGFR-mNSCLC. Methods Medical and pharmacy claims of adults who initiated a subsequent LOT (index) after initial osimertinib discontinuation between November 2015 and September 2019 were analyzed retrospectively. Results A total of 135 patients met the inclusion criteria. After metastatic diagnosis, 22.2% and 49.6% of patients were treated with osimertinib in the first and second line, respectively. After osimertinib discontinuation, most patients were treated with a platinum-based chemotherapy regimen (57%), of which 40.3% included immuno-oncology therapy. Reuse or continuation of EGFR TKIs was also common (24%). Overall, the median time to treatment discontinuation for the index LOT was 2.4 months. Proportions of patients with ≥ 1 inpatient or emergency department visit were 31.9% and 35.6%, respectively. Conclusions The duration of the LOT following osimertinib was short and associated with tolerability issues underscoring a high unmet need for new therapies to address EGFR TKI resistance.