Non-small-cell lung carcinoma (NSCLC) is one of the most common types of lung cancers. The use of tyrosine kinase inhibitors (TKIs) is impeded by the emergence of the Thr790Met mutation in a majority of patients with epidermal growth factor receptor (EGFR)-mutant NSCLC. This study aims to investigate the efficacy and safety of nazartinib (EGF816), a third-gen EGFR TKI in patients with EGFR-mutant NSCLC.

This multicenter, open-label, phase 1/2 study included a total of 180 patients with stage IIIB–IV EGFR-mutant NSCLC. The patients were assigned to receive nazartinib orally, once daily in the following dose levels: 75 mg, 100 mg, 150 mg, 200 mg, 225 mg, 300 mg, and 350 mg. The primary outcome of the study was the maximum tolerated dose of nazartinib.

A total of 7 dose-limiting toxicities were observed during the study. The maximum tolerated dose was not met, but the findings declared 150 mg once daily as the recommended dose. Commonly occurring adverse events were rash (62%), fatigue (30%), and stomatitis (30%). Serious adverse events occurred in 9%, though no deaths were reported during the study.

The research concluded that the recommended dose of nazartinib was 150 mg once daily, and the medication had an acceptable safety profile with low-grade toxicity.