Dacogen

DACOGEN is a cytotoxic drug. Follow special handling and disposal procedures.¹

Aseptically reconstitute DACOGEN with room temperature (20°C to 25°C) 10 mL of Sterile Water for Injection, USP. Upon reconstitution, the final concentration of the reconstituted DACOGEN solution is 5 mg/mL. You must dilute the reconstituted solution with 0.9% Sodium Chloride Injection or 5% Dextrose Injection prior to administration. Temperature of the diluent (0.9% Sodium Chloride Injection or 5% Dextrose Injection) depends on time of administration after preparation.

Fatal and serious myelosuppression occurs in DACOGEN-treated patients. Myelosuppression (anemia, neutropenia, and thrombocytopenia) is the most frequent cause of DACOGEN dose reduction, delay, and discontinuation. Neutropenia of any grade occurred in 90% of DACOGEN-treated patients with grade 3 or 4 occurring in 87% of patients. Grade 3 or 4 febrile neutropenia occurred in 23% of patients. Thrombocytopenia of any grade occurred in 89% of patients with grade 3 or 4 occurring in 85% of patients. Anemia of any grade occurred in 82% of patients. Perform complete blood count with platelets at baseline, prior to each cycle, and as needed to monitor response and toxicity. Manage toxicity using dose-delay, dose-reduction, growth factors, and anti-infective therapies as needed [see Dosage and Administration (2.2)]. Myelosuppression and worsening neutropenia may occur more frequently in the first or second treatment cycles and may not necessarily indicate progression of underlying MDS.

Based on findings from human data, animal studies and its mechanism of action, DACOGEN can cause fetal harm when administered to a pregnant woman [see Clinical Pharmacology (12.1) and Nonclinical Toxicology (13.1)]. In preclinical studies in mice and rats, decitabine caused adverse developmental outcomes including embryo-fetal lethality and malformations. Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception while receiving DACOGEN and for 6 months following the last dose. Advise males with female partners of reproductive potential to use effective contraception while receiving treatment with DACOGEN and for 3 months following the last dose [see Use in Specific Populations (8.1, 8.3)].

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 safety of DACOGEN was studied in 3 single-arm studies (N =66, N =98, N =99) and 1 controlled supportive care study (N =83 DACOGEN, N =81 supportive care). The data described below reflect exposure to DACOGEN in 83 patients in the MDS trial. In the trial, patients received 15 mg/m² intravenously every 8 hours for 3 days every 6 weeks. The median number of DACOGEN cycles was 3 (range 0 to 9).

Most Common Adverse Reactions: neutropenia, thrombocytopenia, anemia, fatigue, pyrexia, nausea, cough, petechiae, constipation, diarrhea, and hyperglycemia.

Adverse Reactions Most Frequently (≥1%) Resulting in Clinical Intervention and or Dose Modification in the Controlled Supportive Care Study in the DACOGEN Arm:

• Discontinuation: thrombocytopenia, neutropenia, pneumonia, Mycobacterium avium complex infection, cardio-respiratory arrest, increased blood bilirubin, intracranial hemorrhage, abnormal liver function tests.
• Dose Delayed: neutropenia, pulmonary edema, atrial fibrillation, central line infection, febrile neutropenia.
• Dose Reduced: neutropenia, thrombocytopenia, anemia, lethargy, edema, tachycardia, depression, pharyngitis.

Table 1 presents all adverse reactions occurring in at least 5% of patients in the DACOGEN group and at a rate greater than supportive care.

In a single-arm MDS study (N=99), DACOGEN was dosed at 20 mg/m² intravenously, infused over one hour daily, for 5 consecutive days of a 4-week cycle. Table 2 presents all adverse reactions occurring in at least 5% of patients.

No overall difference in safety was detected between patients >65 years of age and younger patients in these MDS trials. No significant differences in safety were detected between males and females. Patients with renal or hepatic dysfunction were not studied. Insufficient numbers of non-White patients were available to draw conclusions in these clinical trials.

Serious adverse reactions that occurred in patients receiving DACOGEN not previously reported in Tables 1 and 2 include:

• Allergic Reaction: hypersensitivity (anaphylactic reaction)
• Blood and Lymphatic System Disorders: myelosuppression, splenomegaly
• Cardiac Disorders: myocardial infarction, cardio-respiratory arrest, cardiomyopathy, atrial fibrillation, supraventricular tachycardia
• Gastrointestinal Disorders: gingival pain, upper gastrointestinal hemorrhage
• General Disorders and Administrative Site Conditions: chest pain, catheter site hemorrhage
• Hepatobiliary Disorders: cholecystitis
• Infections and Infestations: fungal infection, sepsis, bronchopulmonary aspergillosis, peridiverticular abscess, respiratory tract infection, pseudomonal lung infection, Mycobacterium avium complex infection
• Injury, Poisoning and Procedural Complications: post procedural pain, post procedural hemorrhage
• Nervous System Disorders: intracranial hemorrhage
• Psychiatric Disorders: mental status changes
• Renal and Urinary Disorders: renal failure, urethral hemorrhage
• Respiratory, Thoracic and Mediastinal Disorders: hemoptysis, lung infiltration, pulmonary embolism, respiratory arrest, pulmonary mass

The following adverse reactions have been identified during postapproval use of DACOGEN. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

• Sweet's syndrome (acute febrile neutrophilic dermatosis)
• Differentiation syndrome
• Interstitial lung disease

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

Of the total number of patients exposed to DACOGEN in the controlled clinical trial, 61 of 83 patients were age 65 years and over, while 21 of 83 patients were age 75 years and over. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

Decitabine is believed to exert its antineoplastic effects after phosphorylation and direct incorporation into DNA and inhibition of DNA methyltransferase, causing hypomethylation of DNA and cellular differentiation or apoptosis. Decitabine inhibits DNA methylation in vitro, which is achieved at concentrations that do not cause major suppression of DNA synthesis. Decitabine-induced hypomethylation in neoplastic cells may restore normal function to genes that are critical for the control of cellular differentiation and proliferation. In rapidly dividing cells, the cytotoxicity of decitabine may also be attributed to the formation of covalent adducts between DNA methyltransferase and decitabine incorporated into DNA. Non-proliferating cells are relatively insensitive to decitabine.

Decitabine has been shown to induce hypomethylation both in vitro and in vivo. However, there have been no studies of decitabine-induced hypomethylation and pharmacokinetic parameters.

Pharmacokinetic (PK) parameters were evaluated in patients. Eleven patients received 20 mg/m² infused over 1 hour intravenously (treatment Option 2). Fourteen patients received 15 mg/m² infused over 3 hours intravenously (treatment Option 1). PK parameters are shown in Table 3. Plasma concentration-time profiles after discontinuation of infusion showed a biexponential decline. The clearance (CL) of decitabine was higher following treatment Option 2. Upon repeat doses, there was no systemic accumulation of decitabine or any changes in PK parameters. Population PK analysis (N=35) showed that the cumulative AUC per cycle for treatment Option 2 was 2.3-fold lower than the cumulative AUC per cycle following treatment Option 1.

The exact route of elimination and metabolic fate of decitabine is not known in humans. One of the pathways of elimination of decitabine appears to be deamination by cytidine deaminase found principally in the liver but also in granulocytes, intestinal epithelium and whole blood.

Carcinogenicity studies with decitabine have not been conducted.

The mutagenic potential of decitabine was tested in several in vitro and in vivo systems. Decitabine increased mutation frequency in L5178Y mouse lymphoma cells, and mutations were produced in an Escherichia coli lac-I transgene in colonic DNA of decitabine-treated mice. Decitabine caused chromosomal rearrangements in larvae of fruit flies.

In male mice given IP injections of 0.15, 0.3 or 0.45 mg/m² decitabine (approximately 0.3% to 1% the recommended clinical dose) 3 times a week for 7 weeks, decitabine did not affect survival, body weight gain or hematological measures (hemoglobin and white blood cell counts). Testes weights were reduced, abnormal histology was observed and significant decreases in sperm number were found at doses ≥0.3 mg/m². In females mated to males dosed with ≥0.3 mg/m² decitabine, pregnancy rate was reduced and preimplantation loss was significantly increased.

A randomized open-label, multicenter, controlled trial evaluated 170 adult patients with myelodysplastic syndromes (MDS) meeting French-American-British (FAB) classification criteria and International Prognostic Scoring System (IPSS) High-Risk, Intermediate-2 and Intermediate-1 prognostic scores. Eighty-nine patients were randomized to DACOGEN therapy plus supportive care (only 83 received DACOGEN), and 81 to Supportive Care (SC) alone. Patients with Acute Myeloid Leukemia (AML) were not intended to be included. Of the 170 patients included in the study, independent review (adjudicated diagnosis) found that 12 patients (9 in the DACOGEN arm and 3 in the SC arm) had the diagnosis of AML at baseline. Baseline demographics and other patient characteristics in the Intent-to-Treat (ITT) population were similar between the 2 groups, as shown in Table 4.

Patients randomized to the DACOGEN arm received DACOGEN intravenously infused at a dose of 15 mg/m² over a 3-hour period, every 8 hours, for 3 consecutive days. This cycle was repeated every 6 weeks, depending on the patient's clinical response and toxicity. Supportive care consisted of blood and blood product transfusions, prophylactic antibiotics, and hematopoietic growth factors. The study endpoints were overall response rate (complete response + partial response) and time to AML or death. Responses were classified using the MDS International Working Group (IWG) criteria; patients were required to be RBC and platelet transfusion independent during the time of response. Response criteria are given in Table 5.

The overall response rate (CR+PR) in the ITT population was 17% in DACOGEN-treated patients and 0% in the SC group (p<0.001) (see Table 6 ). The overall response rate was 21% (12/56) in DACOGEN-treated patients considered evaluable for response (i.e., those patients with pathologically confirmed MDS at baseline who received at least 2 cycles of treatment). The median duration of response (range) for patients who responded to DACOGEN was 288 days (116-388) and median time to response (range) was 93 days (55-272). All but one of the DACOGEN-treated patients who responded did so by the fourth cycle. Benefit was seen in an additional 13% of DACOGEN-treated patients who had hematologic improvement, defined as a response less than PR lasting at least 8 weeks, compared to 7% of SC patients. DACOGEN treatment did not significantly delay the median time to AML or death versus supportive care.

All patients with a CR or PR were RBC and platelet transfusion independent in the absence of growth factors.

Responses occurred in patients with an adjudicated baseline diagnosis of AML.

Three open-label, single-arm, multicenter studies were conducted to evaluate the safety and efficacy of DACOGEN in MDS patients with any of the FAB subtypes. In one study conducted in North America, 99 patients with IPSS Intermediate-1, Intermediate-2, or high-risk prognostic scores received DACOGEN 20 mg/m² as an intravenous infusion over 1-hour daily, on days 1-5 of week 1 every 4 weeks (1 cycle). The results were consistent with the results of the controlled trial and are summarized in Table 8.

Store vials at 20°C to 25°C (68°F to 77°F); excursions permitted between 15°C to 30°C (59°F to 86°F) [See USP Controlled Room Temperature].

Myelosuppression

Advise patients of the risk of myelosuppression and to report any symptoms of infection, anemia, or bleeding to their healthcare provider as soon as possible. Advise patients for the need for laboratory monitoring [see Warnings and Precautions (5.1)].

Embryo-Fetal Toxicity

Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to inform their healthcare provider of a known or suspected pregnancy [see Warnings and Precautions (5.2) and Use in Specific Populations (8.1)].

Advise females of reproductive potential to use effective contraception while receiving DACOGEN and for 6 months after last dose [see Use in Specific Populations (8.3)].

Advise males with female partners of reproductive potential to use effective contraception while receiving treatment with DACOGEN and for 3 months after the last dose [see Use in Specific Populations (8.3) and Nonclinical Toxicology (13.1)].

Lactation

Advise women to avoid breastfeeding while receiving DACOGEN and for at least 2 weeks after the last dose [see Use in Specific Populations (8.2)].