# Characteristics, treatment patterns, and biomarker testing of patients with advanced RET fusion-positive non-small cell lung cancer in a real-world multi-country observational study: a brief report

## TL;DR

This study examines real-world data on patients with RET fusion-positive non-small cell lung cancer, focusing on their clinical features, biomarker testing, and treatment approaches across multiple countries.

## Contribution

The study provides real-world insights into RET fusion-positive non-small cell lung cancer patients, emphasizing the importance of biomarker testing and targeted therapies.

## Key findings

- RET fusion-positive patients were more likely to be White/Caucasian, never smokers, and have adenocarcinoma.
- Only 31% of advanced NSCLC patients were tested for RET fusions, with 84% of results available before treatment initiation.
- The RET fusion-positive cohort showed less use of immunotherapy or targeted therapy compared to the overall cohort.

## Abstract

Approximately 1−2% of non-small cell lung cancers (NSCLCs) are positive for rearranged during transfection (RET) gene fusions. The aim of this real-world multi-national study was to describe clinical characteristics, biomarker testing, and treatment patterns of patients with RET fusion-positive NSCLC.

This observational study was conducted in 2020 in nine countries using electronic patient record forms, following Adelphi Disease Specific Programme (DSP™) methodology. Patients with advanced NSCLC (aNSCLC) were included in the overall cohort. A smaller RET fusion-positive cohort comprised patients from the overall aNSCLC cohort who had RET fusion-positive disease and no other co-alterations, plus an oversample of patients with RET fusion-positive disease and no other co-alterations.

Patient characteristics were generally similar between the overall aNSCLC cohort (n=2947) and the RET fusion-positive cohort (n=576), aside from higher proportions of White/Caucasian patients, never smokers, and adenocarcinoma among the RET fusion-positive cohort. For the overall aNSCLC cohort, 899 (31%) were tested for RET fusions; 84% of RET test results were available prior to initiation of aNSCLC treatment. Comparisons between the two cohorts showed similar proportions of patients treated with chemotherapy (± immunotherapy), but less use of immunotherapy only or targeted therapy in the RET fusion-positive cohort.

Results of this real-world study provide insights into clinical characteristics, biomarker testing, and treatment patterns of patients with RET fusion-positive aNSCLC and highlight the need for awareness and education to increase RET testing with the intent to treat with selective RET inhibitors when appropriate to optimize outcomes for patients.