Abstract
METHODS
In this multicenter observational cohort study in patients with advanced ALK+ NSCLC receiving alectinib treatment, we investigated the association between toxicity, pharmacokinetics, and key genetic variants in ABCB1, CYP3A4, PPAR-α, POR, and CYP3A5. Data on demographics, adverse events, and alectinib trough levels were collected from five hospitals.
CONCLUSIONS
Female patients encounter more severe toxicity due to higher alectinib exposure, which warrants further exploration. PPAR-α 209G>A significantly increased relevant alectinib-induced toxicity, most likely due to an increase in alectinib exposure. Pretreatment testing for genetic variants with a subsequent dose reduction could provide a viable approach to reduce alectinib-related toxicity.
RESULTS
Among 215 patients, 47% experienced severe toxicity. Women experienced more severe toxicity (female versus male: 56% versus 34%; p = 0.001) and had +35% higher alectinib trough levels (p < 0.001). Homozygous carriers of the PPAR-α 209G>A variant exhibited a higher incidence of grade greater than or equal to 3 toxicity (38%) compared with patients who carried at least one wild-type allele (11%) (p = 0.004). This remained significant after Bonferroni correction. Patients who experienced severe toxicity had +18.5% (95% confidence interval: 2.9%-36.6%; p = 0.019) higher trough levels.
INTRODUCTION
Alectinib, a small-molecule kinase inhibitor, is used as first-line treatment for ALK-positive (ALK+) NSCLC. Albeit generally well-tolerated, a considerable subset of patients requires dose adjustments due to drug-related toxicity. Single-nucleotide polymorphisms in genes related to the metabolism of alectinib may upfront identify patients at risk for toxicity.