WHEN MITOXANTRONE IS USED IN HIGH DOSES (> 14 mg/m2/d × 3 days) SUCH AS INDICATED FOR THE TREATMENT OF LEUKEMIA, SEVERE MYELOSUPPRESSION WILL OCCUR. THEREFORE, IT IS RECOMMENDED THAT MITOXANTRONE BE ADMINISTERED ONLY BY PHYSICIANS EXPERIENCED IN THE CHEMOTHERAPY OF THIS DISEASE. LABORATORY AND SUPPORTIVE SERVICES MUST BE AVAILABLE FOR HEMATOLOGIC AND CHEMISTRY MONITORING AND ADJUNCTIVE THERAPIES, INCLUDING ANTIBIOTICS.
BLOOD AND BLOOD PRODUCTS MUST BE AVAILABLE TO SUPPORT PATIENTS DURING THE EXPECTED PERIOD OF MEDULLARY HYPOPLASIA AND SEVERE MYELOSUPPRESSION. PARTICULAR CARE SHOULD BE GIVEN TO ASSURING FULL HEMATOLOGIC RECOVERY BEFORE UNDERTAKING CONSOLIDATION THERAPY (IF THIS TREATMENT IS USED) AND PATIENTS SHOULD BE MONITORED CLOSELY DURING THIS PHASE. MITOXANTRONE ADMINISTERED AT ANY DOSE CAN CAUSE MYELOSUPPRESSION.
CONTAINS SODIUM METABISULFITE, A SULFITE THAT MAY CAUSE ALLERGIC-TYPE REACTIONS INCLUDING ANAPHYLACTIC SYMPTOMS AND LIFE-THREATENING OR LESS SEVERE ASTHMATIC EPISODES IN CERTAIN SUSCEPTIBLE PEOPLE. THE OVERALL PREVALENCE OF SULFITE SENSITIVITY IN THE GENERAL POPULATION IS UNKNOWN AND PROBABLY LOW. SULFITE SENSITIVITY IS SEEN MORE FREQUENTLY IN ASTHMATIC THAN IN NONASTHMATIC PEOPLE.
Patients with preexisting myelosuppression as the result of prior drug therapy should not receive mitoxantrone unless it is felt that the possible benefit from such treatment warrants the risk of further medullary suppression.
The safety of Mitoxantrone Injection, USP (concentrate) in patients with hepatic insufficiency is not established (see CLINICAL PHARMACOLOGY).
Safety for use by routes other than intravenous administration has not been established.
Mitoxantrone is not indicated for subcutaneous, intramuscular, or intra-arterial injection. There have been reports of local/regional neuropathy, some irreversible, following intra-arterial injection.
Mitoxantrone must not be given by intrathecal injection. There have been reports of neuropathy and neurotoxicity, both central and peripheral, following intrathecal injection. These reports have included seizures leading to coma and severe neurologic sequelae, and paralysis with bowel and bladder dysfunction.
Topoisomerase II inhibitors, including mitoxantrone, have been associated with the development of secondary acute myeloid leukemia and myelosuppression.
Because of the possible danger of cardiac effects in patients previously treated with daunorubicin or doxorubicin, the benefit-to-risk ratio of mitoxantrone therapy in such patients should be determined before starting therapy.
Functional cardiac changes including decreases in left ventricular ejection fraction (LVEF) and irreversible congestive heart failure can occur with mitoxantrone. Cardiac toxicity may be more common in patients with prior treatment with anthracyclines, prior mediastinal radiotherapy, or with preexisting cardiovascular disease. Such patients should have regular cardiac monitoring of LVEF from the initiation of therapy. Cancer patients who received cumulative doses of 140 mg/m2 either alone or in combination with other chemotherapeutic agents had a cumulative 2.6% probability of clinical congestive heart failure. In comparative oncology trials, the overall cumulative probability rate of moderate or severe decreases in LVEF at this dose was 13%.
Changes in cardiac function may occur in patients with multiple sclerosis treated with mitoxantrone. In one controlled trial (Study 1, see CLINICAL TRIALS, Multiple Sclerosis), two patients (2%) of 127 receiving mitoxantrone, one receiving a 5 mg/m2 dose and the other receiving the 12 mg/m2 dose, had LVEF values that decreased to below 50%. An additional patient receiving 12 mg/m2, who did not have LVEF measured, had a decrease in another echocardiographic measurement of ventricular function (fractional shortening) that led to discontinuation from the trial (see ADVERSE REACTIONS, Multiple Sclerosis). There were no reports of congestive heart failure in either controlled trial.
MS patients should be assessed for cardiac signs and symptoms by history, physical examination, ECG, and quantitative LVEF evaluation using appropriate methodology (ex. Echocardiogram, MUGA, MRI, etc.) prior to the start of mitoxantrone therapy. MS patients with a baseline LVEF below the lower limit of normal should not be treated with mitoxantrone. Subsequent LVEF and ECG evaluations are recommended if signs or symptoms of congestive heart failure develop and prior to every dose administered to MS patients. Mitoxantrone should not be administered to MS patients who experience a reduction in LVEF to below the lower limit of normal, to those who experience a clinically significant reduction in LVEF, or to those who have received a cumulative lifetime dose of 140 mg/m2. MS patients should have yearly quantitative LVEF evaluation after stopping mitoxantrone to monitor for late-occurring cardiotoxicity.
Acute congestive heart failure may occasionally occur in patients treated with mitoxantrone for ANLL. In first-line comparative trials of mitoxantrone + cytarabine vs daunorubicin + cytarabine in adult patients with previously untreated ANLL, therapy was associated with congestive heart failure in 6.5% of patients on each arm. A causal relationship between drug therapy and cardiac effects is difficult to establish in this setting since myocardial function is frequently depressed by the anemia, fever and infection, and hemorrhage that often accompany the underlying disease.
Hormone-Refractory Prostate Cancer
Functional cardiac changes such as decreases in LVEF and congestive heart failure may occur in patients with hormone-refractory prostate cancer treated with mitoxantrone. In a randomized comparative trial of mitoxantrone plus low-dose prednisone vs low-dose prednisone, 7 of 128 patients (5.5%) treated with mitoxantrone had a cardiac event defined as any decrease in LVEF below the normal range, congestive heart failure (n = 3), or myocardial ischemia. Two patients had a prior history of cardiac disease. The total mitoxantrone dose administered to patients with cardiac effects ranged from > 48 to 212 mg/m2.
Among 112 patients evaluable for safety on the mitoxantrone + hydrocortisone arm of the CALGB trial, 18 patients (19%) had a reduction in cardiac function, 5 patients (5%) had cardiac ischemia, and 2 patients (2%) experienced pulmonary edema. The range of total mitoxantrone doses administered to these patients is not available.
Mitoxantrone may cause fetal harm when administered to a pregnant woman. Women of childbearing potential should be advised to avoid becoming pregnant. Mitoxantrone is considered a potential human teratogen because of its mechanism of action and the developmental effects demonstrated by related agents. Treatment of pregnant rats during the organogenesis period of gestation was associated with fetal growth retardation at doses ≥0.1 mg/kg/day (0.01 times the recommended human dose on a mg/m2 basis). When pregnant rabbits were treated during organogenesis, an increased incidence of premature delivery was observed at doses ≥0.1 mg/kg/day (0.01 times the recommended human dose on a mg/m2 basis). No teratogenic effects were observed in these studies, but the maximum doses tested were well below the recommended human dose (0.02 and 0.05 times in rats and rabbits, respectively, on a mg/m2 basis). There are no adequate and well-controlled studies in pregnant women. Women with multiple sclerosis who are biologically capable of becoming pregnant should have a pregnancy test prior to each dose, and the results should be known prior to administration of the drug. If this drug is used during pregnancy or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential risk to the fetus.
Mitoxantrone therapy increases the risk of developing secondary leukemia in patients with cancer and in patients with multiple sclerosis.
In a study of patients with prostate cancer, acute myeloid leukemia occurred in 1% (5/487) of mitoxantrone-treated patients versus no cases in the control group (0/496) not receiving mitoxantrone at 4.7 years followup.
In a prospective, open-label, tolerability and safety monitoring study of mitoxantrone treated MS patients followed for up to five years (median of 2.8 years), leukemia occurred in 0.6% (3/509) of patients. Publications describe leukemia risk of 0.25% to 2.8% in cohorts of patients with MS treated with mitoxantrone and followed for varying periods of time. This leukemia risk exceeds the risk of leukemia in the general population. The most commonly reported types were acute promyelocytic leukemia and acute myelocytic leukemia.
In 1774 patients with breast cancer who received mitoxantrone concomitantly with other cytotoxic agents and radiotherapy, the cumulative risk of developing treatment-related acute myeloid leukemia was estimated as 1.1% and 1.6% at 5 and 10 years, respectively. The second largest report involved 449 patients with breast cancer treated with mitoxantrone, usually in combination with radiotherapy and/or other cytotoxic agents. In this study, the cumulative probability of developing secondary leukemia was estimated to be 2.2% at 4 years.
Secondary acute myeloid leukemia has also been reported in cancer patients treated with anthracyclines. Mitoxantrone is an anthracenedione, a related drug. The occurrence of secondary leukemia is more common when anthracyclines are given in combination with DNA-damaging antineoplastic agents, when patients have been heavily pretreated with cytotoxic drugs, or when doses of anthracyclines have been escalated.
Symptoms of acute leukemia may include excessive bruising, bleeding, and recurrent infections.
Therapy with mitoxantrone should be accompanied by close and frequent monitoring of hematologic and chemical laboratory parameters, as well as frequent patient observation.
Systemic infections should be treated concomitantly with or just prior to commencing therapy with mitoxantrone.
Information for Patients
Inform patients of the availability of a Medication Guide and instruct them to read the Medication Guide prior to initiating treatment with MitoXANTRONE and prior to each infusion. Review the MitoXANTRONE Medication Guide with every patient prior to initiation of treatment and periodically during treatment. Instruct patients that MitoXANTRONE should be taken only as prescribed.
Advise patients that MitoXANTRONE can cause myelosuppression and inform patients of the signs and symptoms of myelosuppression. Advise patients that MitoXANTRONE can cause congestive heart failure that may lead to death even in people who have never had heart problems before, and inform patients of the signs and symptoms of congestive heart failure. Advise patients receiving MitoXANTRONE to treat multiple sclerosis that they should receive cardiac monitoring prior to each MitoXANTRONE dose and yearly after stopping MitoXANTRONE.
MitoXANTRONE may impart a blue-green color to the urine for 24 hours after administration, and patients should be advised to expect this during therapy. Bluish discoloration of the sclera may also occur.
A complete blood count, including platelets, should be obtained prior to each course of mitoxantrone and in the event that signs and symptoms of infection develop. Liver function tests should also be performed prior to each course of therapy. Mitoxantrone therapy in multiple sclerosis patients with abnormal liver function tests is not recommended because mitoxantrone clearance is reduced by hepatic impairment and no laboratory measurement can predict drug clearance and dose adjustments.
In leukemia treatment, hyperuricemia may occur as a result of rapid lysis of tumor cells by mitoxantrone. Serum uric acid levels should be monitored and hypouricemic therapy instituted prior to the initiation of antileukemic therapy.
Women with multiple sclerosis who are biologically capable of becoming pregnant, even if they are using birth control, should have a pregnancy test, and the results should be known, before receiving each dose of mitoxantrone (see WARNINGS, Pregnancy).
Carcinogenesis, Mutagenesis, Impairment of Fertility
Intravenous treatment of rats and mice, once every 21 days for 24 months, with mitoxantrone resulted in an increased incidence of fibroma and external auditory canal tumors in rats at a dose of 0.03 mg/kg (0.02 fold the recommended human dose, on a mg/m2 basis), and hepatocellular adenoma in male mice at a dose of 0.1 mg/kg (0.03 fold the recommended human dose, on a mg/m2 basis). Intravenous treatment of rats, once every 21 days for 12 months with mitoxantrone resulted in an increased incidence of external auditory canal tumors in rats at a dose of 0.3 mg/kg (0.15 fold the recommended human dose, on a mg/m2 basis).
Mitoxantrone was clastogenic in the in vivo rat bone marrow assay. Mitoxantrone was also clastogenic in two in vitro assays; it induced DNA damage in primary rat hepatocytes and sister chromatid exchanges in Chinese hamster ovary cells. Mitoxantrone was mutagenic in bacterial and mammalian test systems (Ames/Salmonella and E. coli and L5178Y TK+/-mouse lymphoma).
Mitoxantrone and its metabolites are excreted in bile and urine, but it is not known whether the metabolic or excretory pathways are saturable, may be inhibited or induced, or if mitoxantrone and its metabolites undergo enterohepatic circulation. To date, post-marketing experience has not revealed any significant drug interactions in patients who have received mitoxantrone for treatment of cancer. Information on drug interactions in patients with multiple sclerosis is limited.
Following concurrent administration of mitoxantrone with corticosteroids, no evidence of drug interactions has been observed.
Patients with multiple sclerosis who have hepatic impairment should ordinarily not be treated with mitoxantrone. Mitoxantrone should be administered with caution to other patients with hepatic impairment. In patients with severe hepatic impairment, the AUC is more than three times greater than the value observed in patients with normal hepatic function.
Mitoxantrone is excreted in human milk and significant concentrations (18 ng/mL) have been reported for 28 days after the last administration. Because of the potential for serious adverse reactions in infants from mitoxantrone, breast feeding should be discontinued before starting treatment.
Clinical studies of mitoxantrone did not include sufficient numbers of patients aged 65 and over to determine whether they respond differently from younger patients. Other reported clinical experience has not identified differences in responses between the elderly and younger patients.
Hormone-Refractory Prostate Cancer
One hundred forty-six patients aged 65 and over and 52 younger patients (<65 years) have been treated with mitoxantrone in controlled clinical studies. These studies did not include sufficient numbers of younger patients to determine whether they respond differently from older patients. However, greater sensitivity of some older individuals cannot be ruled out.