Pharmacological properties : תכונות פרמקולוגיות

Pharmacodynamic Properties

12.2       Pharmacodynamics
No formal pharmacodynamic studies have been conducted with ZOKINVY.

Pharmacokinetic Properties

12.3       Pharmacokinetics
The pharmacokinetics of lonafarnib at steady state in patients with HGPS following oral administration of lonafarnib twice daily with food are summarized in Table 6.

Table 6: Summary of Pharmacokinetic Parameters of Lonafarnib at Steady State after Oral Administration Twice Daily to Patients with HGPS
Lonafarnib                 Median (range)       Mean (SD)          Mean (SD)         Mean (SD) Dose                          tmax               Cmax             AUC0-8hr          AUCtau (hr)             (ng/mL)          (ng*hr/mL)        (ng*hr/mL)
115 mg/m2       N                 23                 23                 23               15 Results        2 (0, 6)          1777 (1083)        9869 (6327)      12365 (9135) 150 mg/m2       N                 18                 18                 18                8 Results       4 (0, 12)          2695 (1090)       16020 (4978)      19539 (6434) 
Absorption
The absolute bioavailability of lonafarnib following oral administration has not been determined.
Following oral administration of lonafarnib 75 mg and 100 mg twice daily in healthy subjects under fasted conditions, the geometric mean (CV%) maximum peak plasma concentrations of lonafarnib were 834 (32%) ng/mL and 964 (32%) ng/mL, respectively.



Effect of Food
Following a single oral dose of 75 mg lonafarnib in healthy subjects, the Cmax decreased 55% and AUC decreased 29% with a high-fat meal (approximately 43% fat of the total 952 calories) compared to fasted conditions. Cmax decreased 25% and AUC decreased 21% with a low-fat meal (approximately 12% fat of the total 421 calories) compared to fasted conditions.

Distribution
In vitro plasma protein binding of lonafarnib was greater than or equal to 99% over the concentration range between 0.5 to 40.0 μg/mL. The apparent volumes of distribution were 87.8 L and 97.4 L, respectively, at steady state following oral administration of lonafarnib 100 mg and 75 mg twice daily in healthy subjects.

Elimination
The mean half-life was approximately 4 to 6 hours following oral administration of lonafarnib 100 mg twice daily in healthy subjects.

Metabolism
Lonafarnib is primarily metabolized by CYP3A and to a lesser extent by CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2C19, and CYP2E1 in vitro.

Excretion
Following an oral administration of 104 mg [14C]-lonafarnib under fasted conditions in healthy subjects, approximately 62% of the total radiolabeled dose was recovered in feces and <1% of the total radiolabeled dose was recovered in urine up to 240 hours post-dose. The two most predominant metabolites were HM17 and HM21 (an active metabolite) accounting for 15% and 14% of plasma radioactivity, respectively.

Specific Populations

Patients with Renal Impairment or Hepatic Impairment
ZOKINVY has not been studied in patients with renal impairment or in patients with hepatic impairment.

Male and Female Patients
Following a single oral dose of 100 mg lonafarnib in healthy subjects, the plasma lonafarnib AUC and Cmax were 44% and 26% higher in female subjects, respectively, compared to male subjects.
The observed exposure difference by sex in healthy subjects is not considered clinically meaningful.

Geriatric Patients
Following a single oral dose of 100 mg lonafarnib in healthy subjects, the plasma lonafarnib AUC and Cmax were 59% and 27% higher in subjects ≥65 years, respectively, compared to subjects 18 to 45 years of age. The observed higher exposure in geriatric subjects is not considered clinically relevant.



Drug Interaction Studies

In Vitro Studies
Lonafarnib is a CYP3A substrate and a potent CYP3A time-dependent and mechanism-based inhibitor. Lonafarnib is an inhibitor of CYP2C8 and CYP2C19. Lonafarnib is not considered an inhibitor of CYP1A2, CYP2B6, CYP2C8, CYP2C9, or CYP2D6. Lonafarnib is unlikely to be an inducer of CYP1A2, CYP2B6, and CYP3A.

Lonafarnib is not a substrate of transporters OATP1B1, OATP1B3, or BCRP, but is likely a marginal substrate of P-gp. Lonafarnib is an inhibitor of P-gp, OATP1B1, OATP1B3, and BCRP.

Clinical Studies: Effects of other Drugs on Lonafarnib

CYP3A inhibitors
Lonafarnib is a sensitive substrate for CYP3A. With coadministration of a single oral dose of 50 mg lonafarnib following 200 mg ketoconazole (a strong CYP3A inhibitor) once daily for 5 days, the Cmax and AUC of lonafarnib were increased by 270% and 425%, respectively, as compared to lonafarnib administered alone in healthy subjects [see Dosage and Administration (2.3),
Contraindications (4), Drug Interactions (7.1)].

CYP2C9 inhibitors
Coadministration with CYP2C9 inhibitors may increase lonafarnib AUC and Cmax. A drug-drug interaction study of ZOKINVY with CYP2C9 inhibitors has not been conducted [see Drug Interactions (7.1)].

CYP3A inducers
With coadministration of a single oral dose of 50 mg lonafarnib (combined with a single oral dose of 100 mg ritonavir) following 600 mg rifampin once daily for 8 days, the Cmax of lonafarnib was reduced by 92% and the AUC was reduced by 98%, as compared to without rifampin coadministration in healthy subjects [see Contraindications (4), Drug Interactions (7.1)].

Clinical Studies: Effects of Lonafarnib on other Drugs

CYP3A Substrates
Lonafarnib is a strong inhibitor of CYP3A. With coadministration of a single oral dose of 3 mg midazolam with multiple oral doses of 100 mg lonafarnib twice daily for 5 days in healthy subjects, the Cmax and AUC of midazolam were increased by 180% and 639%, respectively [see Dosage and Administration (2.4), Contraindications (4), Drug Interactions (7.2)].

Loperamide
With coadministration of a single oral 2 mg dose of loperamide (primarily metabolized by CYP2C8 and CYP3A and a substrate of P-gp) with multiple oral doses of lonafarnib 100 mg twice daily for 5 days in healthy subjects, the Cmax and AUC of loperamide were increased by 214% and 299%, respectively [see Drug Interactions (7.2)].

CYP2C19 Substrates
Lonafarnib is a moderate CYP2C19 inhibitor. With coadministration of a single oral dose of 40 mg omeprazole with multiple oral doses of lonafarnib 75 mg twice daily for 5 days in healthy subjects, the Cmax and AUC of omeprazole were increased by 28% and 60%, respectively [see Drug Interactions (7.2)].

P-gp and OATP1B Substrates
With coadministration of a single oral dose of 180 mg fexofenadine (a P-gp and OATP1B substrate) with multiple oral doses of 100 mg lonafarnib twice daily for 5 days in healthy subjects, the Cmax and AUC of fexofenadine were increased by 21% and 24%, respectively [see Drug Interactions (7.2)].