e of 50 ng/mL to 1000 ng/mL with α1-acid-glycoprotein (AAG) being the principal binding protein.
Metabolism
Romidepsin undergoes extensive metabolism in vitro primarily by CYP3A4 with minor contribution from CYP3A5, CYP1A1, CYP2B6, and CYP2C19. At therapeutic concentrations, romidepsin did not competitively inhibit CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1, or CYP3A4 in vitro.
Excretion
Following 4-hour intravenous administration of romidepsin at 14 mg/m2 on days 1, 8 and 15 of a 28-day cycle in patients with T cell lymphomas, the terminal half-life (t1/2) was approximately 3 hours. No accumulation of plasma concentration of romidepsin was observed after repeated dosing.
Effect of Age, Gender or Race
The population pharmacokinetic analysis of romidepsin showed that age, gender, or race (white vs black) did not appear to influence the pharmacokinetics of romidepsin.
Effect of Hepatic Impairment
No dedicated hepatic impairment study has been conducted for ISTODAX. The population pharmacokinetic analysis indicates that mild hepatic impairment [total bilirubin (TB) ≤ upper limit of normal (ULN) and aspartate aminotransferase (AST) > ULN; or TB > 1.0x - 1.5x ULN and any AST] had no significant influence on romidepsin pharmacokinetics. As the effect of moderate (TB > 1.5x - 3x ULN and any AST) and severe (TB > 3x ULN and any AST) hepatic impairment on the pharmacokinetics of romidepsin is unknown, patients with moderate and severe hepatic impairment should be treated with caution [See Use in Specific Populations (8.6)].
Effect of Renal Impairment
No dedicated renal impairment study has been conducted for ISTODAX. The population pharmacokinetic analysis showed that romidepsin pharmacokinetics were not affected by mild (estimated creatinine clearance 50 - 80 mL/min), moderate (estimated creatinine clearance 30 - 50 mL/min), or severe (estimated creatinine clearance < 30 mL/min) renal impairment. Nonetheless, the effect of end-stage renal disease on romidepsin pharmacokinetics has not been studied. Thus, patients with end-stage renal disease should be treated with caution [See Use in Specific Populations (8.7)].
13 NONCLINICAL TOXICOLOGY
13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility
Carcinogenicity studies have not been performed with romidepsin. Romidepsin was not mutagenic in vitro in the bacterial reverse mutation assay (Ames test) or the mouse lymphoma assay. Romidepsin was not clastogenic in an in vivo rat bone marrow micronucleus assay when tested to the maximum tolerated dose (MTD) of 1 mg/kg in males and 3 mg/kg in females (6 and 18 mg/m2 in males and females, respectively). These doses were up to 1.3-fold the recommended human dose, based on body surface area.
Based on non-clinical findings, male and female fertility may be compromised by treatment with ISTODAX. In a 26-week toxicology study, romidepsin administration resulted in testicular degeneration in rats at 0.33 mg/kg/dose (2 mg/m2/dose) following the clinical dosing schedule. This dose resulted in AUC0-inf. values that were approximately 2% the exposure level in patients receiving the recommended dose of 14 mg/m2/dose. A similar effect was seen in mice after 4 weeks of drug administration at higher doses. Seminal vesicle and prostate organ weights were decreased in a separate study in rats after 4 weeks of daily drug administration at 0.1 mg/kg/day (0.6 mg/m2/day), approximately 30% the estimated human daily dose based |
