High incidence and reversible bradycardia events following alectinib initiation

With the widespread use of alectinib in patients with anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer (NSCLC), its cardiotoxicity has gradually emerged, including new-onset sinus bradycardia (SB). However, the incidence, timing, severity, and risk factors of alectinib-induced bradycardia remain unknown.

From January 2020 to June 2022, 93 patients with ALK-positive NSCLC treated with alectinib were enrolled in this retrospective analysis. These patients had heart rate (HR) recorded before and after alectinib administration. By reviewing electronic medical records and follow-up, the HR changes of patients during medication were recorded. The potential risk factors associated with alectinib-induced SB were explored.

According to an HR cut-off of 60 beats per minute (bpm), 47 patients (50.54%) experienced at least one recorded bradycardia. The mean HR of total participants before alectinib administration was 78.32 (standard deviation [SD], 9.48) and after was 64.88 (SD, 12.21). The median maximum change in HR (range) for all patients was 11 (-55, +4) bpm. For the bradycardia subgroup, the HR of most patients (76.60%) hovered around 50-60 bpm, and 61.70% of SB occurred within 3 months after alectinib administration. Multivariate analysis indicated that baseline HR (odds ratio [OR] 0.86, 95% confidence interval [CI] 0.79-0.93, p < 0.001) and history of hypertension (OR 13.71, 95% CI 2.49-76.38, p = 0.003) were independent risk factors for alectinib-related bradycardia.

Alectinib-induced bradycardia had a high incidence, appeared relatively early, and was reversible by dose reduction or withdrawal.