Phase 1 study to evaluate the effects of rifampin or itraconazole on the pharmacokinetics of limertinib (ASK120067), a novel mutant-selective inhibitor of the epidermal growth factor receptor in healthy Chinese subjects.

Background: Limertinib is a novel mutant-selective and irreversible inhibitor of the epidermal growth factor receptor under development. A phase 1 open, two-period, single-sequence, self-controlled, two-part study was initiated to characterize the effects of a strong CYP3A4 inducer (rifampin) or inhibitor (itraconazole) on the pharmacokinetics of limertinib.

Research Design And Methods: Twenty-four healthy subjects in each part received a single dose of limertinib alone (160 mg, Part A; 80 mg, Part B) and with multiple doses of rifampin 600 mg once daily (Part A) or itraconazole 200 mg twice daily (Part B).

Results: Coadministration of rifampin decreased exposure (area under the plasma concentration-time curve from time 0 to infinity, AUC) of limertinib and its active metabolite CCB4580030 by 87.86% (geometric least-squares mean [GLSM] ratio, 12.14%; 90% confidence interval [CI], 9.89-14.92) and 66.82% (GLSM ratio, 33.18%; 90% CI, 27.72-39.72), respectively. Coadministration of itraconazole increased the AUC of limertinib by 289.8% (GLSM ratio, 389.8%; 90% CI, 334.07-454.82), but decreased that of CCB4580030 by 35.96% (GLSM ratio, 64.04%; 90% CI, 50.78-80.77).

Conclusions: Our study demonstrates that the concomitant use of limertinib with strong CYP3A inducers or inhibitors is not recommended. A single dose of limertinib, administered with or without rifampin or itraconazole, is generally safe and well tolerated in healthy Chinese subjects.

Clinical Trial Registration: www.clinicaltrials.gov identifier is NCT05631678.