Mitoxantrone in worsening secondary progressive multiple sclerosis: A prospective, open-label study

Results from the 5-year, phase IV RENEW (Registry to Evaluate Novantrone Effects in Worsening Multiple Sclerosis) study

Background

Registry to Evaluate Novantrone Effects in Worsening Multiple Sclerosis (RENEW) was a 5-year, phase IV study in which the safety of Mitoxantrone was monitored in a patient cohort from the United States (US). The objective of the study was to evaluate the long-term safety profile of Mitoxantrone in patients with secondary progressive multiple sclerosis (SPMS), progressive relapsing multiple sclerosis (PRMS), and worsening relapsing-remitting multiple sclerosis (RRMS).

Methods

Overall, 509 patients (395 SPMS, 81 worsening RRMS, 33 PRMS) were enrolled and treated at 46 multiple sclerosis (MS) treatment centers located in the US. Patients received Mitoxantrone in accordance with the package insert every 3 months. During the treatment phase, patients received laboratory workups and cardiac monitoring every 3 months and then annually for a total of 5 years.

Results

Five hundred and nine subjects were enrolled in this trial and received at least one infusion of Mitoxantrone. Overall, 172 (33.8%) completed the 5-year trial (i.e., participated for 5 years ± 3 months [treatment + follow-up]); 337 (66.2%) did not complete the 5-year trial. Annual follow-up data were available for 250 of 509 enrolled patients. Left ventricular ejection fraction reduction under 50% was reported in 27 (5.3%) patients during the treatment phase (n = 509) and 14 (5.6%) patients during the annual follow-up phase (n = 250). Signs and symptoms of congestive heart failure were observed in 10 (2.0%) patients (six during treatment phase and four during the annual follow-up phase). Post-hoc analyses of the risk for cardiotoxicity outcomes revealed that cumulative dose exposure is the primary risk factor associated with the risk of cardiac toxicity with Mitoxantrone. Therapy-related leukemia was reported in three (0.6%) patients who received total cumulative Mitoxantrone doses of 73.5 mg/m², 107.3 mg/m², and 97.1 mg/m² respectively. During the treatment phase, persistent amenorrhea developed in 22% (28/128) of women with regular menses and 51% (25/49) of women with irregular menses at baseline. During the annual follow-up phase, persistent amenorrhea developed in 5% (4/73) of women with regular menses at baseline.

Conclusion

RENEW results are consistent with the known safety profile of Mitoxantrone, and provide additional long-term safety data for Mitoxantrone in MS patients.

Evidence Report: The efficacy and safety of mitoxantrone (Novantrone) in the treatment of multiple sclerosis: Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology

OBJECTIVE

The chemotherapeutic agent mitoxantrone was approved for use in multiple sclerosis (MS) in 2000. After a review of all the available evidence, the original report of the Therapeutics and Technology Assessment Subcommittee in 2003 concluded that mitoxantrone probably reduced clinical attack rates, MRI activity, and disease progression. Subsequent reports of decreased systolic function, heart failure, and leukemia prompted the US Food and Drug Administration to institute a "black box" warning in 2005. This review was undertaken to examine the available literature on the efficacy and safety of mitoxantrone use in patients with MS since the initial report.

METHODS

Relevant articles were obtained through a review of the medical literature and the strength of the available evidence was graded according to the American Academy of Neurology evidence classification scheme.

RESULTS

The accumulated Class III and IV evidence suggests an increased incidence of systolic dysfunction and therapy-related acute leukemia (TRAL) with mitoxantrone therapy. Systolic dysfunction occurs in approximately 12% of patients with MS treated with mitoxantrone, congestive heart failure occurs in approximately 0.4%, and leukemia occurs in approximately 0.8%. The number needed to harm is 8 for systolic dysfunction and 123 for TRAL. There is no new efficacy evidence that would change the recommendation from the previous report.

CONCLUSIONS

The risk of systolic dysfunction and leukemia in patients treated with mitoxantrone is higher than suggested at the time of the previous report, although comprehensive postmarketing surveillance data are lacking.