A real-world study of PD-L1 testing patterns and PD-1/PD-L1 inhibitor therapy in patients with metastatic non-small cell lung cancer: An analysis of the Sotiria Hospital lung cancer registry

INTRODUCTION Real-world data on programmed death-ligand 1 (PD-L1) testing and biomarker-guided treatment in patients with advanced/metastatic non-small cell lung cancer (mNSCLC) are lacking. METHODS This non-interventional, retrospective study used patient data from the lung cancer registry of the Sotiria Hospital in Greece. Included patients had mNSCLC and initiated first line (L) treatment from August 2016 (when pembrolizumab gained reimbursement) to August 2019; patient follow-up ended in August 2020. The study mainly assessed the PD-L1 testing rates and the treatment(s) prescribed by epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) status, and PD-L1 tumor proportion score (TPS). Data were descriptively analyzed. Kaplan-Meier estimates of time- to-event outcomes were generated. RESULTS Of 705 patients, 304 (43.1%) were tested for PD-L1 expression during observation. PD-L1 testing rates reached 73.8% across quarters Q1- Q3 of 2019; most patients were tested at 1L. At 1L, 59.3% of patients with EGFR/ALK negative or unknown status and PD-L1 TPS >_50% received PD-1/ PD-L1 inhibitors; 90.6% of these patients received pembrolizumab. Regardless of PD-L1 expression levels, most patients with EGFR/ALK negative or unknown status received PD-1/PD-L1 inhibitors at 2L. The numerically highest 1L median overall survival for patients with EGFR/ALK negative or unknown status was attained with PD-1/PD-L1 inhibitors, with overall survival (OS) of 26.7 months. CONCLUSIONS PD-L1 testing rates increased rapidly following the reimbursement of pembrolizumab in the 1L treatment of patients with mNSCLC. Patients with EGFR/ALK negative or unknown status and PD-L1 TPS >_50% most frequently received PD-1/PD-L1 inhibitors at 1L, and attained longer OS compared with other therapies.