Romidepsin Injection

Dosing Information

The recommended dose of romidepsin is 14 mg/m2 administered intravenously over a 4-hour period on days 1, 8, and 15 of a 28-day cycle. Cycles should be repeated every 28 days provided that the patient continues to benefit from and tolerates the drug.

Dose Modification

Nonhematologic toxicities except alopecia

• Grade 2 or 3 toxicity: Treatment with romidepsin should be delayed until toxicity returns to ≤ Grade 1 or baseline, then therapy may be restarted at 14 mg/m2. If Grade 3 toxicity recurs, treatment with romidepsin should be delayed until toxicity returns to ≤ Grade 1 or baseline and the dose should be permanently reduced to 10 mg/m2.
• Grade 4 toxicity: Treatment with romidepsin should be delayed until toxicity returns to ≤ Grade 1 or baseline, then the dose should be permanently reduced to 10 mg/m2.
• Romidepsin should be discontinued if Grade 3 or 4 toxicities recur after dose reduction.

Hematologic toxicities

• Grade 3 or 4 neutropenia or thrombocytopenia: Treatment with romidepsin should be delayed until the specific cytopenia returns to ANC ≥1.5×109/L and platelet count ≥75×109/L or baseline, then therapy may be restarted at 14 mg/m2.
• Grade 4 febrile (≥ 38.5ºC) neutropenia or thrombocytopenia that requires platelet transfusion: Treatment with romidepsin should be delayed until the specific cytopenia returns to ≤ Grade 1 or baseline, and then the dose should be permanently reduced to 10 mg/m2.

Instructions for Preparation and Intravenous Administration

Romidepsin is a cytotoxic drug. Use appropriate handling procedures.

Romidepsin must be reconstituted with the supplied diluent and further diluted with 0.9% Sodium Chloride Injection, USP before intravenous infusion.

Romidepsin and diluent vials contain an overfill to ensure the recommended volume can be withdrawn at a concentration of 5 mg/mL.

• Each 10 mg single-dose vial of romidepsin must be reconstituted with 2.2 mL of the supplied diluent.
• With a suitable syringe, aseptically withdraw 2.2 mL from the supplied diluent vial, and slowly inject it into the romidepsin for injection vial. Swirl the contents of the vial until there are no visible particles in the resulting solution. The reconstituted solution will contain romidepsin 5 mg/mL. The reconstituted romidepsin vial will contain 2 mL of deliverable volume of drug product. The reconstituted romidepsin solution is chemically stable for up to 8 hours at room temperature.
• Extract the appropriate amount of romidepsin from the vials to deliver the desired dose, using proper aseptic technique. Before intravenous infusion, further dilute romidepsin in 500 mL 0.9% Sodium Chloride Injection, USP.
• Infuse over 4 hours.

The diluted solution is compatible with polyvinyl chloride (PVC), ethylene vinyl acetate (EVA), polyethylene (PE) infusion bags as well as glass bottles, and is chemically stable for up to 24 hours when stored at room temperature. However, it should be administered as soon after dilution as possible.

Parenteral drug products should be inspected visually for particulate matter and discoloration before administration, whenever solution and container permit.

Romidepsin is supplied as a kit which includes a sterile, lyophilized powder in a 10 mg single-dose vial containing 11 mg of romidepsin and 22 mg of the bulking agent, povidone, USP. In addition, each kit includes a single-dose sterile vial containing 2.4 mL (2.2 mL deliverable volume) of the diluent composed of 80% propylene glycol, USP, and 20% dehydrated alcohol, USP.

None.

No specific information is available on the treatment of overdosage of romidepsin.

Toxicities in a single-dose study in rats or dogs, at intravenous romidepsin doses up to 2.2 fold the recommended human dose based on the body surface area, included irregular respiration, irregular heartbeat, staggering gait, tremor, and tonic convulsions.

In the event of an overdose, it is reasonable to employ the usual supportive measures, e.g., clinical monitoring and supportive therapy, if required. There is no known antidote for romidepsin and it is not known if romidepsin is dialyzable.

Romidepsin, a histone deacetylase (HDAC) inhibitor, is a bicyclic depsipeptide. At room temperature, romidepsin is a white powder and is described chemically as (1S,4S,7Z,10S,16E,21R)-7-ethylidene-4,21-bis(1-methylethyl)-2-oxa-12,13-dithia-5,8,20,23-tetraazabicyclo[8.7.6]tricos-16-ene-3,6,9,19,22-pentone. The empirical formula is C24H36N4O6S2.

The molecular weight is 540.71 and the structural formula is:

Romidepsin for injection is intended for intravenous infusion only after reconstitution with the supplied diluent and after further dilution with 0.9% Sodium Chloride, USP.

Romidepsin is supplied as a kit containing 2 vials.

Romidepsin for injection is a sterile lyophilized white powder and is supplied in a 10 mg single-dose vial containing 11 mg romidepsin and 22 mg povidone, USP.

Diluent for romidepsin is a sterile clear solution and is supplied in a single-dose vial containing 2.4 mL (2.2 mL deliverable volume). Diluent for romidepsin contains 80% (v/v) propylene glycol, USP and 20% (v/v) dehydrated alcohol, USP.

Mechanism of Action

Romidepsin is a histone deacetylase (HDAC) inhibitor. HDACs catalyze the removal of acetyl groups from acetylated lysine residues in histones, resulting in the modulation of gene expression. HDACs also deacetylate non-histone proteins, such as transcription factors. In vitro, romidepsin causes the accumulation of acetylated histones, and induces cell cycle arrest and apoptosis of some cancer cell lines with IC50 values in the nanomolar range. The mechanism of the antineoplastic effect of romidepsin observed in nonclinical and clinical studies has not been fully characterized.

Pharmacodynamics

Cardiac Electrophysiology

The effect of romidepsin on the heart-rate corrected QTc/QTcF was evaluated in 26 subjects with advanced malignancies given romidepsin at doses of 14 mg/m2 as a 4-hour intravenous infusion, and at doses of 8, 10 or 12 mg/m2 as a 1–hour infusion. Patients received premedications with antiemetics. No large changes in the mean QTc interval (> 20 milliseconds) from baseline based on Fridericia correction method were detected in the trial. Small increase in mean QT interval (< 10 milliseconds) and mean QT interval increase between 10 to 20 milliseconds cannot be excluded because of the limitations in the trial design.

Romidepsin was associated with a delayed concentration-dependent increase in heart rate in patients with advanced cancer with a maximum mean increase in heart rate of 20 beats per minute occurring at the 6 hour time point after start of romidepsin infusion for patients receiving 14 mg/m2 as a 4-hour infusion.

Pharmacokinetics

Absorption

Romidepsin exhibited linear pharmacokinetics across doses ranging from 1.0 to 24.9 mg/m2 when administered intravenously over 4 hours in patients with advanced cancers.

In patients with T-cell lymphomas who received 14 mg/m2 of romidepsin intravenously over a 4-hour period on days 1, 8, and 15 of a 28-day cycle, geometric mean values of the maximum plasma concentration (Cmax) and the area under the plasma concentration versus time curve (AUC0-∞) were 377 ng/mL and 1549 ng*hr/mL, respectively.

Distribution

Romidepsin is highly protein bound in plasma (92% to 94%) over the concentration range of 50 ng/mL to 1000 ng/mL with α1-acid-glycoprotein (AAG) being the principal binding protein. Romidepsin is a substrate of the efflux transporter P-glycoprotein (P-gp, ABCB1).

In vitro, romidepsin accumulates into human hepatocytes via an unknown active uptake process. Romidepsin is not a substrate of the following uptake transporters: BCRP, BSEP, MRP2, OAT1, OAT3, OATP1B1, OATP1B3, or OCT2. In addition, romidepsin is not an inhibitor of BCRP, MRP2, MDR1 or OAT3. Although romidepsin did not inhibit OAT1, OCT2, and OATP1B3 at concentrations seen clinically (1 μmol/L), modest inhibition was observed at 10 µmol/L. Romidepsin was found to be an inhibitor of BSEP and OATP1B1.

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.

At therapeutic concentrations, romidepsin did not cause notable induction of CYP1A2, CYP2B6 and CYP3A4 in vitro. Therefore, pharmacokinetic drug-drug interactions are unlikely to occur due to CYP450 induction or inhibition by romidepsin when co-administered with CYP450 substrates.

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 (t½) was approximately 3 hours. No accumulation of plasma concentration of romidepsin was observed after repeated dosing.

Drug Interactions

Ketoconazole: A drug interaction clinical trial with the strong CYP3A4 inhibitor, ketoconazole, was conducted in patients with advanced cancer. Following co-administration of 8 mg/m2 romidepsin (4-hour infusion) with ketoconazole, the overall romidepsin exposure was increased by approximately 25% and 10% for AUC0-∞ and Cmax, respectively, compared to romidepsin alone, and the difference in AUC0-∞ between the 2 treatments was statistically significant. Co-administration of ketoconazole slightly decreased the romidepsin clearance and volume of distribution, but did not have a statistically significant effect on peak exposure (Cmax) [see Drug Interactions (7.2)].

Rifampin: A drug interaction clinical trial with the strong CYP3A4 inducer, rifampin, was conducted in patients with advanced cancer. Following co-administration of 14 mg/m2 romidepsin (4-hour infusion) with rifampin, the overall romidepsin exposure was unexpectedly increased by approximately 80% and 60% for AUC0-∞ and Cmax, respectively, compared to romidepsin alone, and the difference between the 2 treatments was statistically significant. Co-administration of rifampin decreased the romidepsin clearance and volume of distribution by 44% and 52%, respectively. The increase in exposure seen after co-administration with rifampin is likely due to rifampin's inhibition of an undetermined hepatic uptake process that is predominant for the disposition of romidepsin [see Drug Interactions (7.3)].

Use in Specific Populations

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 romidepsin. 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 romidepsin. 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)].