The pharmacokinetics of olutasidenib have been characterized in patients with AML following the approved recommended dosage, unless otherwise specified.
The mean (%CV) olutasidenib steady-state daily area under the plasma drug concentration over time curve (AUC0-12-h,ss) is 43050 (34.0%) ng·h/mL and steady-state maximum plasma concentration (Cmax,ss) is 3573 (45.6%) ng/mL following the approved recommended dosage.
Olutasidenib Cmax and AUC increase less-than proportionally over a dosage range from 100 mg to 300 mg (0.33 to 1 time the recommended total daily dose); however, this finding should not affect the recommended dosage of REZLIDHIA. Olutasidenib accumulation ratios ranging from 7.7 and 9.5 were observed following the approved recommended dosage. Steady-state plasma levels are reached within 14 days.
Absorption
The median (min, max) time to maximum concentration (tmax) of olutasidenib is approximately 4 (1, 8) hours following a single oral dose of 150 mg.
Effect of Food
The mean (CV%) of olutasidenib Cmax increased by 191% (20.6%) and AUCinf increased by 83% (18.3%) following administration of a single 150 mg dose of olutasidenib with a high-fat meal (approximately 800 to 1,000 calories, with approximately 50% of total caloric content of the meal from fat) in healthy subjects.
Distribution
The mean (CV%) apparent volume of distribution of olutasidenib is 319 (28.1%) L. The plasma protein binding of olutasidenib is approximately 93%.
Elimination
The mean (CV%) half-life (t1⁄2) of olutasidenib is approximately 67 (51.2%) hours and the mean (CV%) apparent oral clearance (CL/F) of olutasidenib is 4 (60.5%) L/h.
Metabolism
Olutasidenib metabolism involves N-dealkylation, demethylation, oxidative deamination followed by oxidation, mono-oxidation with subsequent glucuronidation. Olutasidenib is primarily (90%) metabolized by cytochrome P450(CYP)3A4, with minor contributions from CYP2C8, CYP2C9, CYP1A2, and CYP2C19.
Excretion
Following a single oral radiolabeled olutasidenib dose of 150 mg to healthy subjects, approximately 75% of olutasidenib was recovered in feces (35% unchanged) and 17% in the urine (1% unchanged).
Specific Populations
No clinically significant differences in the pharmacokinetics of olutasidenib were observed based on age (28 to 90 years), sex, body weight (36 to 145 kg), mild to moderate renal impairment (creatinine clearance [CLcr] 30 to <90mL/min as estimated by Cockcroft-Gault), or mild (total bilirubin ≤ULN and any AST >ULN or total bilirubin >1 to 1.5 times ULN and any AST) or moderate (total bilirubin >1.5 to 3 times ULN and any AST) hepatic impairment.
The effect of severe renal impairment (CLcr 15 to 29 mL/min, as estimated by Cockcroft-Gault), kidney failure (CLcr <15 mL/min, as estimated by Cockcroft-Gault), patients on dialysis, and patients with severe hepatic impairment (total bilirubin >3 x ULN with any AST) on olutasidenib pharmacokinetics is unknown or not fully characterized.
Drug Interaction Studies
Clinical Studies
Strong CYP3A and P-glycoprotein (P-gp) Inhibitors: No clinically significant differences in olutasidenib pharmacokinetics were observed when used concomitantly with multiple doses of a strong CYP3A and P-gp inhibitor (itraconazole).
Strong CYP3A4 Inducers: Olutasidenib Cmax decreased by 43% and AUC by 80% when used concomitantly with multiple doses of a strong CYP3A inducer (rifampin).
In vitro Studies
CYP Enzymes: Olutasidenib induces CYP3A4, CYP2B6, CYP1A2, CYP2C8 and CYP2C9.
Olutasidenib does not inhibit CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4/5.
Transporter Systems: Olutasidenib is not a substrate of BCRP, BSEP, MRP2, MRP3, or MRP4.
Ivosidenib does not inhibit BCRP, OATP1B1, OATP1B3, OAT1, and OCT2 at clinically relevant concentrations. Ivosidenib is an inhibitor of OAT3 and P-gp.
Olutasidenib is an inhibitor of P-gp, BCRP, OATP1B1, OATP1B3, OAT3, OCT2, MATE1, and MATE2K. Olutasidenib does not inhibit BSEP, MRP2, MRP3, MRP4, or OAT1.