The cardiac effects of mitoxantrone: do the benefits in multiple sclerosis outweigh the risks?

Mitoxantrone, an immunosuppressant agent with potent anti-inflammatory activity, has been used to treat patients with multiple sclerosis (MS) who have worsening relapsing-remitting (RRMS) or secondary progressive multiple sclerosis (SPMS) despite prior therapy with interferons or glatiramer acetate. From previous experience of treating cancer with mitoxantrone, it was expected that cardiotoxic effects and occasional malignancy would develop in some patients treated with this agent. From the earliest trials, reduction of left ventricular ejection fraction (LVEF) was seen in 2-3% of cases, and in some this effect may persist and less commonly there can be congestive heart failure and even death. There are also occasional reports of leukaemia developing in MS patients treated with this agent. Mitoxantrone has been shown to reduce relapses, the number of new lesions visualised on magnetic resonance imaging and stop or reduce the progression of the disease in many patients treated. The drug has found a place in MS therapy because in this progressing group of MS patients who are failing on the disease-modifying therapies with interferons or glatiramer acetate, trials have shown that mitoxantrone may arrest or even improve many patients. Recognising the risks, mitoxantrone therapy is a reasonable option for MS patients with RRMS and SPMS who are progressing despite current disease-modifying therapy.