General

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.

Cardiac Effects

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%.

Pregnancy

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.

Secondary Leukemia

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.

General

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

See FDA-approved patient labeling (MEDICATION GUIDE).

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.

Laboratory Tests

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

Drug Interactions

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.

Special Populations

Pregnancy

(see WARNINGS).

Nursing Mothers

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.

Pediatric Use

Safety and effectiveness in pediatric patients have not been established.

Geriatric Use