2.1 Dosage Information

The recommended dosage 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.

2.2 Dosage Modification

Nonhematologic toxicities except alopecia

•

Grade 2 or 3 toxicity: Treatment with romidepsin should be delayed until toxicity returns to Grade 0-1 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 0-1 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 0-1 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 greater than or equal to 1.5×109/L and platelet count greater than or equal to 75×109/L or baseline, then therapy may be restarted at 14 mg/m2.

•

Grade 4 febrile (greater than or equal to 38.5ºC) neutropenia or thrombocytopenia that requires platelet transfusion: Treatment with romidepsin should be delayed until the specific cytopenia returns to less than or equal to Grade 1 or baseline, and then the dose should be permanently reduced to 10 mg/m2.

2.3 Dosage in Patients with Hepatic Impairment

For patients with moderate or severe hepatic impairment, reduce the starting dose of ISTODAX as shown in Table 1 and monitor for toxicities more frequently. Dosage adjustment is not required for patients with mild hepatic impairment.

2.4 Instructions for Preparation and Intravenous Administration

ISTODAX is a hazardous drug. Use appropriate handling procedures.1

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

ISTODAX and diluent vials contain an overfill to ensure the recommended volume can be withdrawn at a concentration of 5 mg/mL.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 ISTODAX 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 ISTODAX (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 ISTODAX 5 mg/mL. The reconstituted ISTODAX vial will contain 2 mL of deliverable volume of drug product. The reconstituted ISTODAX solution is chemically stable for up to 8 hours at room temperature.

•

Extract the appropriate amount of ISTODAX from the vials to deliver the desired dose, using proper aseptic technique. Before intravenous infusion, further dilute ISTODAX 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.

5.1 Myelosuppression

Treatment with ISTODAX can cause thrombocytopenia, leukopenia (neutropenia and lymphopenia), and anemia. Monitor blood counts regularly during treatment with ISTODAX and modify the dose as necessary [see Dosage and Administration (2.2) and Adverse Reactions (6.1)].

5.2 Infections

Fatal and serious infections have been reported in clinical trials of ISTODAX, including pneumonia, sepsis, and viral reactivation, including reactivation of Epstein Barr and hepatitis B viruses. These infections can occur during and following treatment. The risk of life-threatening infections may be greater in patients with a history of prior treatment with monoclonal antibodies directed against lymphocyte antigens and in patients with disease involvement of the bone marrow [see Adverse Reactions (6.1)].

Reactivation of hepatitis B virus infection was reported in 1% of patients in clinical trials. In patients with evidence of prior hepatitis B infection, consider monitoring for reactivation, and consider antiviral prophylaxis.

Reactivation of Epstein Barr viral infection leading to liver failure has occurred in recipients of ISTODAX including after ganciclovir prophylaxis.

5.3 Electrocardiographic Changes

Several treatment-emergent morphological changes in ECGs (including T-wave and ST-segment changes) have been reported in clinical studies. The clinical significance of these changes is unknown [see Adverse Reactions (6.1)].

In patients with congenital long QT syndrome, patients with a history of significant cardiovascular disease, and patients taking anti-arrhythmic medicines or medicinal products that lead to significant QT prolongation, consider cardiovascular monitoring of ECGs at baseline and periodically during treatment.

Confirm that potassium and magnesium levels are within normal range before administration of ISTODAX [see Adverse Reactions (6.1)].

5.4 Tumor Lysis Syndrome

Tumor lysis syndrome (TLS) has been reported to occur in recipients of ISTODAX, including in 1% of patients with tumor stage CTCL. Patients with advanced stage disease and/or high tumor burden are at greater risk, should be closely monitored, and managed as appropriate.

5.5 Embryo-Fetal Toxicity

Based on its mechanism of action and findings from animal studies, ISTODAX can cause fetal harm when administered to a pregnant woman. In an animal reproductive study, romidepsin was embryocidal and caused adverse developmental outcomes at exposures below those in patients at the recommended dose of 14 mg/m2. Advise females of reproductive potential to use effective contraception during treatment and for 1 month after the last dose. Advise males with female partners of reproductive potential to use effective contraception during treatment and for 1 month after the last dose [see Use in Specific Populations (8.1, 8.3) and Clinical Pharmacology (12.1)].

6.1 Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The data in the WARNINGS AND PRECAUTIONS reflect exposure to ISTODAX in four clinical trials involving 363 patients with T-cell lymphoma, including 185 patients with CTCL. ISTODAX was administered as a single agent at a dosage of 14 mg/m2 on days 1, 8, and 15 of a 28-day cycle. Among 363 patients who received ISTODAX, 21% were exposed for 6 months or longer and 13% were exposed for greater than one year.

7.1 Warfarin or Coumarin Derivatives

Prolongation of PT and elevation of INR were observed in a patient receiving ISTODAX concomitantly with warfarin. Monitor PT and INR more frequently in patients concurrently receiving ISTODAX and warfarin [see Clinical Pharmacology (12.3)].

7.2 Drugs That Inhibit CYP3A4 Enzymes

Strong CYP3A4 inhibitors increase concentrations of romidepsin [see Clinical Pharmacology (12.3)]. Monitor for toxicity related to increased romidepsin exposure and follow the dose modifications for toxicity [see Dosage and Administration (2.2)] when ISTODAX is initially co-administered with strong CYP3A4 inhibitors.

7.3 Drugs That Induce CYP3A4 Enzymes

Rifampin (a potent CYP3A4 inducer) increased the concentrations of romidepsin [see Clinical Pharmacology (12.3)]. Avoid co-administration of ISTODAX with rifampin. The use of other potent CYP3A4 inducers should be avoided when possible.

8.1 Pregnancy

8.2 Lactation

8.3 Females and Males of Reproductive Potential

ISTODAX can cause fetal harm when administered to a pregnant woman [see Use in Specific Populations (8.1)].

8.4 Pediatric Use

The safety and effectiveness of ISTODAX in pediatric patients have not been established.

8.5 Geriatric Use

Of the 186 patients with CTCL who received ISTODAX in clinical studies, 51 (28%) were 65 years of age and older, while 16 (9%) were 75 years of age. No overall differences in safety or effectiveness were observed between patients 65 years or age and over and younger patients; however, greater sensitivity of some older individuals cannot be ruled out.

8.6 Hepatic Impairment

In a hepatic impairment study, ISTODAX was evaluated in 19 patients with advanced cancer and mild (8), moderate (5), or severe (6) hepatic impairment. There were 4 deaths during the first cycle of treatment: 1 patient with mild hepatic impairment, 1 patient with moderate hepatic impairment, and 2 patients with severe hepatic impairment. No dose adjustments are recommended for patients with mild hepatic impairment. Reduce the ISTODAX starting dose for patients with moderate and severe hepatic impairment [see Dosage and Administration (2.3) and Clinical Pharmacology (12.3)]. Monitor patients with hepatic impairment more frequently for toxicity, especially during the first cycle of therapy.

12.1 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.

12.2 Pharmacodynamics

Cardiac Electrophysiology

At doses of 14 mg/m2 as a 4-hour intravenous infusion, and at doses of 8 (0.57 times the recommended dose), 10 (0.71 times the recommended dose) or 12 (0.86 times the recommended dose) mg/m2 as a 1-hour infusion, no large changes in the mean QTc interval (>20 milliseconds) from baseline based on Fridericia correction method were detected. Small increase in mean QT interval (< 10 milliseconds) and mean QT interval increase between 10 to 20 milliseconds cannot be excluded.

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.

12.3 Pharmacokinetics

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. Romidepsin exhibited linear pharmacokinetics across doses ranging from 1.0 (0.07 times the recommended dose) to 24.9 (1.76 times the recommended dose) mg/m2 when administered intravenously over 4 hours in patients with advanced cancers.

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 nonclinical 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-∞ 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 on body surface area. Romidepsin showed high affinity for binding to estrogen receptors in pharmacology studies. In a 26-week toxicology study in rats, atrophy was seen in the ovary, uterus, vagina and mammary gland of females administered doses as low as 0.1 mg/kg/dose (0.6 mg/m2/dose) following the clinical dosing schedule. This dose resulted in AUC0-∞ values that were 0.3% of those in patients receiving the recommended dose of 14 mg/m2/dose. Maturation arrest of ovarian follicles and decreased weight of ovaries were observed in a separate study in rats after 4 weeks of daily drug administration at 0.1 mg/kg/day (0.6 mg/m2/day). This dose is approximately 30% the estimated human daily dose based on body surface area.