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.

Table 4a summarizes clinical adverse events of all intensities occurring in ≥5% of patients in either dose group of mitoxantrone and that were numerically greater on drug than on placebo in Study 1. The majority of these events were of mild to moderate intensity, and nausea was the only adverse event that occurred with severe intensity in more than one patient (three patients [5%] in the 12 mg/m2 group). Of note, alopecia consisted of mild hair thinning.

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).

Table 4b summarizes laboratory abnormalities that occurred in ≥ 5% of patients in either mitoxantrone dose group, and that were numerically more frequent than in the placebo group.

There was no difference among treatment groups in the incidence or severity of hemorrhagic events.

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.

Leukopenia and neutropenia were reported in the M + MP group (see Table 5b).

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 M + 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.