Long-term follow-up of pediatric patients treated with mitoxantrone for multiple sclerosis

The chemotherapeutic agent mitoxantrone is approved for the treatment of aggressive multiple sclerosis (MS) in adults. Its use, however, is limited by the risk of severe adverse events including cardiotoxicity, myelosuppression, liver toxicity and secondary leukemia. The aim of this retrospective study is to present data on the safety, tolerability and efficacy of mitoxantrone in a small cohort of children with MS. 4 pediatric MS patients with a high relapse rate or severe, disabling relapses were treated with mitoxantrone and followed for 3.8-18 years. The cumulative dose of mitoxantrone was 36, 68, 84 and 120 mg/m (2), respectively. The frequency and severity of relapses as well as disability scores, decreased in the year after treatment onset. Short-term adverse events were transient in all cases. Cardiac monitoring by transthoracic echocardiography (TTE) showed asymptomatic left ventricular dysfunction during treatment in 1 patient, which was again normal at the next assessment. Long-term adverse events, including late-onset mitoxantrone-induced cardiotoxicity or secondary leukemia did not occur during the follow-up period. In our cohort of pediatric MS patients, mitoxantrone showed short-term reduction of disease activity and no long-term adverse events on follow-up. However, the risk of mitoxantrone-induced cardiotoxicity or toxic leukemia remains a life-long threat.