Drug Interaction Report

Coadministration with inhibitors of CYP450 2C9 may increase the plasma concentrations of ensifentrine. According to the prescribing information, ensifentrine's primary routes of metabolism are oxidative (hydroxylation and O-demethylation) followed by conjugation. Additionally, in vitro data indicates ensifentrine is predominantly metabolized by CYP450 2C9, and to a lesser extent by CYP450 2D6. When ensifentrine (3 mg single dose) was coadministered with the CYP450 2C9 inhibitor fluconazole (200 mg twice daily) to 28 healthy volunteers, ensifentrine systemic exposure (AUC) increased by 1.6-fold and peak plasma concentration (Cmax) increased by 1.4-fold. The increase in ensifentrine exposure by fluconazole was not considered clinically relevant.

ADJUST DOSING INTERVAL: Food may reduce the oral bioavailability of asciminib. When a single 40 mg dose of asciminib was administered with a low-fat meal (400 calories; 25% fat) in healthy volunteers, asciminib peak plasma concentration (Cmax) and systemic exposure (AUC) decreased by 35% and 30%, respectively, compared to asciminib administered in the fasted state. Administration with a high-fat meal (1000 calories; 50% fat) decreased the Cmax and AUC of asciminib by 68% and 62%, respectively.

MANAGEMENT: To ensure adequate asciminib exposures, food consumption should be avoided for at least 2 hours before and 1 hour after taking asciminib.