Effects of CYP3A4 genetic polymorphisms on the pharmacokinetics and efficacy of perampanel in Chinese pediatric patients with epilepsy

Objective: This study was the first to evaluate the effect of CYP3A4 gene polymorphisms on the plasma concentration and effectiveness of perampanel (PER) in Chinese pediatric patients with epilepsy. Methods: We enrolled 102 patients for this investigation. The steady-state concentration was determined after patients maintained a consistent PER dosing regimen for at least 21 days. Plasma PER concentrations were measured using liquid chromatography-tandem mass spectrometry. Leftover samples from standard therapeutic drug monitoring were allocated for genotyping analysis. The primary measure of efficacy was the rate of seizure reduction with PER treatment at the final check-up. Results: The CYP3A4x10 GC phenotype exhibited the highest average plasma concentration of PER at 491.1 +/- 328.1 ng/mL, in contrast to the CC phenotype at 334.0 +/- 161.1 ng/mL. The incidence of adverse events was most prominent in the CYP3A4x1 G TT and CYP3A4x10 GC groups, with rates of 77.8 % (7 of 9 patients) and 50.0 % (46 of 92 patients), respectively. Moreover, the percentage of patients for whom PER was deemed ineffective was least in the CYP3A4x1 G TT and CYP3A4x10 CC groups, recorded at 11.1 % (1 of 9 patients) and 10.0 % (1 of 10 patients), respectively. There was a significant correlation between PER plasma concentration and either exposure or toxicity (both with p < 0.05). We suggest a plasma concentration range of 625-900 ng/mL as a suitable reference for PER in Chinese patients with epilepsy. Conclusion: The CYP3A4x10 gene's genetic polymorphisms influence plasma concentrations of PER in Chinese pediatric patients with epilepsy. Given that both efficacy and potential toxicity are closely tied to plasma PER levels, the CYP3A4 genetic phenotype should be factored in when prescribing PER to patients with epilepsy.