Drug Interactions between belumosudil and vorasidenib

ADJUST DOSING INTERVAL: Administration with food increases the oral bioavailability of belumosudil. The mechanism has not been described. Administration of belumosudil (200 mg single oral dose) in healthy subjects, with a fatty and calorie-rich meal (approximately half of the calories were contained in the fat) increased the mean belumosudil peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) by 120% and 100%, respectively, compared to administration under fasting conditions. The time to reach peak concentration (Tmax) was delayed by 30 minutes. Administration of oral belumosudil 200 mg once daily with food in patients with chronic graft-versus-host disease (chronic GVHD) lead to steady-state concentrations of the drug with an accumulation ration of 1.4.

MANAGEMENT: To ensure maximal oral absorption, belumosudil should be administered with a meal, every day at the same time.

GENERALLY AVOID: Due to induction of CYP450 1A2, the isoenzyme primarily responsible for the metabolic clearance of vorasidenib, smoking tobacco during treatment with vorasidenib may decrease its plasma concentrations and anti-tumor effect. Clinical and pharmacokinetic data are currently lacking.

MANAGEMENT: Patient should be advised to avoid smoking tobacco during treatment with vorasidenib because it may reduce efficacy of the therapy.