Cardiac Safety Assessment of Lazertinib: Findings From Patients With Mutation-Positive Advanced NSCLC and Preclinical Studies.

Introduction: Lazertinib is a potent, irreversible, brain-penetrant, mutant-selective, and wild-type-sparing third-generation EGFR tyrosine kinase inhibitor (TKI), creating a wide therapeutic index. Cardiovascular adverse events (AEs), including QT prolongation, decreased left ventricular ejection fraction (LVEF), and heart failure, have emerged as potential AEs with certain EGFR TKI therapies.

Methods: Cardiac safety of lazertinib was evaluated in TKI-tolerant adults with mutation-positive locally advanced or metastatic NSCLC receiving lazertinib (20-320 mg/d). QT intervals corrected with Fridericia's formula (QTcF) prolongation, time-matched concentration-QTcF relationship, change of LVEF, and cardiac failure-associated AEs were evaluated. The clinical findings were supplemented by the following three preclinical studies: an in vitro hERG inhibition assay, an ex vivo isolated perfused rabbit heart study, and an in vivo telemetry-instrumented beagle dog study.

Results: Preclinical evaluation revealed little to no physiological effect on the basis of electrocardiogram, electrophysiological, proarrhythmic, and hemodynamic parameters. Clinical evaluation of 181 patients revealed no clinically relevant QTcF prolongation by centralized electrocardiogram in any patient and at any dose level. The predicted magnitude of QTcF value increase at maximum steady-state plasma concentration for the therapeutic dose of lazertinib (240 mg/d) was 2.2 msec (upper bound of the two-sided 90% confidence interval: 3.6 msec). No patient had clinically relevant LVEF decrease (i.e., minimum postbaseline LVEF value of <50% and a maximum decrease in LVEF value from baseline of ≥10 percentage points). Cardiac failure-associated AE occurred in one patient (grade 2 decreased LVEF) and resolved without any dose modifications.

Conclusions: Our first-in-human study, together with preclinical data, indicates that lazertinib is not associated with increased cardiac risk.