Absorption
Following multiple oral administrations under fed conditions, maximum plasma concentration of venetoclax was reached 5-8 hours after dose. Venetoclax steady state AUC increased proportionally over the dose range of 150-800 mg. Under low-fat meal conditions, venetoclax mean (± standard deviation) steady state Cmax was 2.1 ± 1.1 μg/mL and AUC0-24 was32.8 ± 16.9 μg•h/mL at the 400 mg once daily dose.
Food Effect
Administration with a low-fat meal increased venetoclax exposure by approximately 3.4-fold and administration with a high-fat meal increased venetoclax exposure by 5.1- to 5.3-fold compared to fasting conditions. Venetoclax should be administered with a meal [see Dosage and Administration (2.2)].
Distribution
Venetoclax is highly bound to human plasma protein with unbound fraction in plasma <0.01 across a concentration range of 1-30 µM (0.87-26 µg/mL). The mean blood-to-plasma ratio was 0.57. The population estimate for apparent volume of distribution (Vdss/F) of venetoclax ranged from 256-321 L in patients.
Elimination
The population estimate for the terminal elimination half-life of venetoclax was approximately 26 hours. The pharmacokinetics of venetoclax does not change over time.
Metabolism
In vitro studies demonstrated that venetoclax is predominantly metabolized by CYP3A4/5. M27 was identified as a major metabolite in plasma with an inhibitory activity against BCL-2 that is at least 58-fold lower than venetoclax in vitro.
Excretion
After single oral administration of 200 mg radiolabeled [14C]-venetoclax dose to healthy subjects, >99.9% of the dose was recovered in feces and <0.1% of the dose was excreted in urine within 9 days, indicating that hepatic elimination is responsible for the clearance of venetoclax from the systemic circulation. Unchanged venetoclax accounted for 20.8% of the administered radioactive dose excreted in feces.
Special Populations
Age, Race, Sex, and Weight
Based on population pharmacokinetic analyses, age, race, sex, and weight do not have a clinically meaningful effect on venetoclax clearance.
Renal Impairment
Based on a population pharmacokinetic analysis that included 211 subjects with mild renal impairment (CrCl ≥60 and <90 mL/min, calculated by Cockcroft-Gault equation), 83 subjects with moderate renal impairment (CrCl ≥30 and <60 mL/min) and 210 subjects with normal renal function (CrCl ≥90 mL/min), venetoclax exposures in subjects with mild or moderate renal impairment are similar to those with normal renal function. The pharmacokinetics of venetoclax has not been studied in subjects with severe renal impairment (CrCl <30 mL/min) or subjects on dialysis [see Use in Specific Populations (8.6)].
Hepatic Impairment
Based on a population pharmacokinetic analysis that included 69 subjects with mild hepatic impairment, 7 subjects with moderate hepatic impairment and 429 subjects with normal hepatic function, venetoclax exposures are similar in subjects with mild and moderate hepatic impairment and normal hepatic function. The NCI Organ Dysfunction Working Group criteria for hepatic impairment were used in the analysis. Mild hepatic impairment was defined as normal total bilirubin and aspartate transaminase (AST) > upper limit of normal (ULN) or total bilirubin >1.0 to 1.5 times ULN, moderate hepatic impairment as total bilirubin >1.5 to 3.0 times ULN, and severe hepatic impairment as total bilirubin >3.0 times ULN. The pharmacokinetics of venetoclax has not been studied in subjects with severe hepatic impairment [see Use in Specific Populations (8.7)].
Drug Interactions
Ketoconazole
Co-administration of 400 mg once daily ketoconazole, a strong CYP3A, P-gp and BCRP inhibitor, for 7 days in 11 previously treated NHL patients increased venetoclax Cmax by 2.3-fold and AUC∞ by 6.4-fold [see Drug Interactions (7.1)].
Ritonavir
Co-administration of 50 mg once daily ritonavir, a strong CYP3A, P-gp and OATP1B1/B3 inhibitor, for 14 days in 6 healthy subjects increased venetoclax Cmax by 2.4-fold and AUC by 7.9-fold [see Drug Interactions (7.1)].
Rifampin multiple doses
Co-administration of 600 mg once daily rifampin, a strong CYP3A inducer, for 13 days in 10 healthy subjects decreased venetoclax Cmax by 42% and AUC∞ by 71% [see Drug Interactions (7.1)].
Rifampin single dose
Co-administration of a 600 mg single dose of rifampin, an OATP1B1/1B3 and P-gp inhibitor, in 11 healthy subjects increased venetoclax Cmax by 106% and AUC∞ by 78% [see Drug Interactions (7.1)].
Azithromycin
In a drug-drug interaction study in 12 healthy subjects, co-administration of 500 mg of azithromycin on the first day followed by 250 mg of azithromycin for 4 days decreased venetoclax Cmax by 25% and AUC∞ by 35%. No dose adjustment is needed when venetoclax is co-administered with azithromycin.
Gastric Acid Reducing Agents
Based on population pharmacokinetic analysis, gastric acid reducing agents (e.g., proton pump inhibitors, H2-receptor antagonists, antacids) do not affect venetoclax bioavailability.
Warfarin
In a drug-drug interaction study in three healthy subjects, administration of a single 400 mg dose of venetoclax with 5 mg warfarin resulted in 18% to 28% increase in Cmax and AUC∞ of R-warfarin and S-warfarin [see Drug Interactions (7.2)].
Digoxin
In a drug-drug interaction study in 10 healthy subjects, administration of a single 100 mg dose of venetoclax with 0.5 mg digoxin, a P-gp substrate, resulted in a 35% increase in digoxin Cmax and a 9% increase in AUC∞[see Drug Interactions (7.2)].
In vitro Studies
In vitro studies indicated that venetoclax is not an inhibitor or inducer of CYP1A2, CYP2B6, CYP2C19, CYP2D6, or CYP3A4 at clinically relevant concentrations. Venetoclax is a weak inhibitor of CYP2C8, CYP2C9, and UGT1A1 in vitro, but it is not predicted to cause clinically relevant inhibition due to high plasma protein binding. Venetoclax is not an inhibitor of UGT1A4, UGT1A6, UGT1A9, or UGT2B7.
Venetoclax is a P-gp and BCRP substrate as well as a P-gp and BCRP inhibitor and weak OATP1B1 inhibitor in vitro. Venetoclax is not expected to inhibit OATP1B3, OCT1, OCT2, OAT1, OAT3, MATE1, or MATE2K at clinically relevant concentrations.