Multiple Sclerosis Society of London Website - linkMitoxantrone is a potent immunosuppressant used in the treatment of some forms of cancer. It is licensed in the US for the treatment of worsening relapsing remitting MS and relapsing progressive MS. This study investigated the effectiveness of mitoxantrone as a "rescue therapy" for people taking beta interferon who continued to experience disabling relapses or significant disability progression.
Ten people who experienced more than three relapses a month and had rapid disability progression took part in the study. Neurological assessments, MRI scans and blood tests, both to monitor ongoing inflammation, were completed initially, every three months and within three days of a relapse. After six months receiving just beta interferon participants received three infusions of mitoxantrone into the vein, in combination with steroids, shown to shorten the recovery time after a relapse, once monthly. After an additional six months of just beta interferon therapy people who did not show a benefit from the first combination therapy again received intravenous infusions of mitoxantrone, in addition to beta interferon therapy, at the rate of once every three months. All participants were monitored for the following 15-18 months.

During the first three months of mitoxantrone treatment none of the participants experienced any relapses and disability levels stabilised. The amount of inflammation present also significantly decreased compared to levels present during beta interferon therapy alone. During the following six months of just beta interferon treatment the relapse rate remained significantly reduced and inflammation levels remained low. Disability levels for seven of the 10 participants remained stable after the initial mitoxantrone treatment. The remaining three participants received additional mitoxantrone, as described. During further mitoxantrone treatment these participants experienced no new relapses and their disability stabilised. Overall, mitoxantrone was well tolerated with a low number of adverse events reported.

In conclusion, mitoxantrone administered concurrently with beta interferon was effective in significantly reducing both the relapse rate and levels of inflammation in people with MS. It also effectively stabilised disability progression in people with rapidly progressive disease. Positive effects were still detectable after 15 months. The authors highlight that further studies of agents for rapidly progressing MS are warranted.