MITOXANTRONE has been administered to 149 patients with multiple sclerosis in two randomized clinical trials, including 21 patients who received MITOXANTRONE in combination with corticosteroids.
In Study 1, the proportion of patients who discontinued treatment due to an adverse event was 9.7% (n = 6) in the 12 mg/m² MITOXANTRONE arm (leukopenia, depression, decreased LV function, bone pain and emesis, renal failure, and one discontinuation to prevent future complications from repeated urinary tract infections) compared to 3.1% (n = 2) in the placebo arm (hepatitis and myocardial infarction). The following clinical adverse experiences were significantly more frequent in the MITOXANTRONE groups: nausea, alopecia, urinary tract infection, and menstrual disorders, including amenorrhea.
Two of the 127 patients treated with MITOXANTRONE in Study 1 had decreased LVEF to below 50% at some point during the 2 years of treatment. An additional patient receiving 12 mg/m² did not have LVEF measured, but had another echocardiographic measure of ventricular function (fractional shortening) that led to discontinuation from the study.
The proportion of patients experiencing any infection during Study 1 was 67% for the placebo group, 85% for the 5 mg/m² group, and 81% for the 12 mg/m² group. However, few of these infections required hospitalization: one placebo patient (tonsillitis), three 5 mg/m² patients (enteritis, urinary tract infection, viral infection), and four 12 mg/m² patients (tonsillitis, urinary tract infection [two], endometritis).
In Study 2, MITOXANTRONE was administered once a month. Clinical adverse events most frequently reported in the MITOXANTRONE group included amenorrhea (53% of female patients), alopecia (33% of patients), nausea (29% of patients), and asthenia (24% of patients). Tables 5a and 5b respectively summarize adverse events and laboratory abnormalities occurring in > 5% of patients in the MITOXANTRONE group and numerically more frequent than in the control group.
Neutropenia occurred within 3 weeks after MITOXANTRONE administration and was always reversible. Only mild to moderate intensity infections were reported in 9 of 21 patients in the N +MP group and in 3 of 21 patients in the MP group; none of these required hospitalization. There was no difference among treatment groups in the incidence or severity of hemorrhagic events. There were no withdrawals from Study 2 for safety reasons.
MITOXANTRONE has been studied in approximately 600 patients with acute nonlymphocytic leukemia (ANLL). Table 6 represents the adverse reaction experience in the large U.S. comparative study of mitoxantrone + cytarabine vs daunorubicin + cytarabine. Experience in the large international study was similar. A much wider experience in a variety of other tumor types revealed no additional important reactions other than cardiomyopathy (see WARNINGS). It should be appreciated that the listed adverse reaction categories include overlapping clinical symptoms related to the same condition, e.g., dyspnea, cough and pneumonia. In addition, the listed adverse reactions cannot all necessarily be attributed to chemotherapy as it is often impossible to distinguish effects of the drug and effects of the underlying disease. It is clear, however, that the combination of MITOXANTRONE + cytarabine was responsible for nausea and vomiting, alopecia, mucositis/stomatitis, and myelosuppression.
Adverse reactions are presented as major categories and selected examples of clinically significant subcategories.
Detailed safety information is available for a total of 353 patients with hormone-refractory prostate cancer treated with MITOXANTRONE, including 274 patients who received MITOXANTRONE in combination with corticosteroids.
Hypotension, urticaria, dyspnea, and rashes have been reported occasionally. Anaphylaxis/anaphylactoid reactions have been reported rarely.
Extravasation at the infusion site has been reported, which may result in erythema, swelling, pain, burning, and/or blue discoloration of the skin. Extravasation can result in tissue necrosis with resultant need for debridement and skin grafting. Phlebitis has also been reported at the site of the infusion.
Topoisomerase II inhibitors, including MITOXANTRONE, in combination with other antineoplastic agents or alone, have been associated with the development of acute leukemia (see WARNINGS).
Myelosuppression is rapid in onset and is consistent with the requirement to produce significant marrow hypoplasia in order to achieve a response in acute leukemia. The incidences of infection and bleeding seen in the U.S. trial are consistent with those reported for other standard induction regimens.
Hormone-Refractory Prostate Cancer
In a randomized study where dose escalation was required for neutrophil counts greater than 1000/mm³, Grade 4 neutropenia (ANC < 500 /mm³) was observed in 54% of patients treated with MITOXANTRONE + low-dose prednisone. In a separate randomized trial where patients were treated with 14 mg/m², Grade 4 neutropenia in 23% of patients treated with MITOXANTRONE + hydrocortisone was observed. Neutropenic fever/infection occurred in 11% and 10% of patients receiving MITOXANTRONE + corticosteroids, respectively, on the two trials. Platelets < 50,000/mm³ were noted in 4% and 3% of patients receiving MITOXANTRONE + corticosteroids on these trials, and there was one patient death on MITOXANTRONE + hydrocortisone due to intracranial hemorrhage after a fall.
Nausea and vomiting occurred acutely in most patients and may have contributed to reports of dehydration, but were generally mild to moderate and could be controlled through the use of antiemetics. Stomatitis/mucositis occurred within 1 week of therapy.
Congestive heart failure, tachycardia, EKG changes including arrhythmias, chest pain, and asymptomatic decreases in left ventricular ejection fraction have occurred. (See WARNINGS)
Interstitial pneumonitis has been reported in cancer patients receiving combination chemotherapy that included MITOXANTRONE.