A Real-World Study of Patients with Advanced Non-squamous Non-small Cell Lung Cancer with EGFR Exon 20 Insertion: Clinical Characteristics and Outcomes

Abstract

Background: In Europe, few data regarding the characteristics of EGFR exon 20 insertion (20ins) mutations in non-small cell lung cancer (NSCLC) are available.

Objective: Using a large real-world cohort, we assessed the incidence, characteristics, and outcomes of patients with non-squamous (nsq) NSCLC harboring EGFR exon 20ins.

Patients and methods: The Epidemio-Strategy and Medical Economics advanced and metastatic lung cancer data platform including advanced/metastatic nsqNSCLC patients from January 2015 was analyzed (cut-off date: June 30, 2020). Characteristics, epidermal growth factor receptor (EGFR) mutation and other mutations, treatment patterns, and clinical outcomes were assessed for patients harboring EGFR exon 20ins, common EGFR mutations, other EGFR mutations, and wild-type EGFR. Survival parameters were estimated by the Kaplan-Meier method in these four groups.

Results: Out of 9435 nsqNSCLC patients tested for EGFR, 1549 (16.4%) had a mutation, including 61 with EGFR exon 20ins (3.9% of all mutated EGFR). These 61 patients had a mean age of 63.6 years, were mostly female (68.9%) and non-smokers (55.7%), with de novo stage IV disease (73.8%) and performance status 0-1 (76.9%). Almost all patients (95.1%) with exon 20ins received systemic therapy (median, three lines). First-line systemic treatments consisted mainly of combination chemotherapy (70.7%), single-agent EGFR tyrosine kinase inhibitors (10.3%), and single-agent immunotherapy (5.2%). After a median follow-up of 25.0 (95% confidence interval [CI] 22.3-32.4) months, the median real-world overall survival was 24.3 (19.1-32.6) months in patients with exon 20ins compared to 35.4 (95% CI 32.6-37.5) in patients with common EGFR mutation (n = 1049) (p = 0.049) and 19.6 (95% CI 18.6-20.5) in patients with wild-type EGFR (n = 7866) (p = 0.2).

Conclusions: This large national study in nsqNSCLC patients confirms that EGFR exon 20ins is a rare condition (0.6%). The prognosis associated with exon 20ins appears to be in line with that of wild-type EGFR, but worse than common EGFR mutations, highlighting the need for advancements for this rare population.