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.

Therapy-related acute leukemia in two patients with multiple sclerosis treated with Mitoxantrone

Two cases of therapy-related acute leukemia (TRAL) after the use of Mitoxantrone for the treatment of secondary progressive multiple sclerosis (MS) are reported. They were extracted from the group of 42 consecutive patients with TRAL diagnosed and treated in single centre between 2000-2010. They were the only two with MS and the only two treated with Mitoxantrone. The first patient was a 43-year-old male with a previous history of MS of 15-year-duration, who developed acute promyelocytic leukemia 9 months following Mitoxantrone therapy (cumulative dose 120 mg). The second patient was a 55-year-old female suffering from MS for 16 years, who developed acute mixed-phenotype leukemia, T/myeloid type, with 46,XX,del(7)(p13)[12]/47,XX,idem,+3/[6]/46,XX[2], 15 months after completion of Mitoxantrone therapy (cumulative dose 100mg). Acute mixed-phenotype leukemia, T/myeloid type is for the first time described in the context of prior Mitoxantrone therapy. Although the incidence of TRAL in relation to Mitoxantrone pretreatment is rare, we should be vigilant for the prompt identification of this adverse event.