Pixantrone another potent DMT similar to Mitoxantrone without the cardiotoxicity

Gonsette R, Debouverie M, Sindic C, Ferré JC, Edan G.
Mult Scler. 2015 Aug 18. pii: 1352458515601902 Pixantrone: a B-cell-depleting immunosuppressant for multiple sclerosis patients with active disease. [Epub ahead of print]
BACKGROUND:Mitoxantrone has been approved for patients with worsening relapsing-remitting (RR) or secondary progressive multiple sclerosis(SPMS), but its long-term use is limited by its cardiotoxicity. Pixantrone (PIX) is an analog of mitoxantrone.
OBJECTIVES:The aim of this open-label, multicenter, noncomparative Phase I/II trial was to explore the immunosuppressive effect of PIX, its impact on clinical disease activity and cerebral gadolinium-enhanced (Gd+) lesions, and its safety.
METHODS:Eighteen patients with active RRMS and SPMS (⩾ 1 cerebral Gd+ lesion) despite approved immunomodulatory therapy received four intravenous PIX injections every 21 days. A neurological examination, hematology, lymphocyte subsets, and biochemistry were performed at Day 1, Weeks 3, 6 and 9, and Months 3, 6, 9 and 12. Echocardiography was performed before each infusion, at Months 3, 6 and 12. Cerebral MRI was performed at baseline, and at Months 6 and 12.
RESULTS:CD19+ cells were reduced by 95% at Month 3 and by 47% at Month 12. Gd+ lesions were reduced by 86% at Month 12 (p = 0.01). The annual relapse rate was reduced by 87% (p < 10-4). Two patients experienced a transient reduction in left ventricular fraction.
CONCLUSION: These preliminary data indicate the efficacy of PIX in active RRMS and SPMS.
It is interesting that as CD-20 immunotherapy appears to be coming to the market that a desirable feature of a drug is now B cell depleting rather than T cell depletion. However any drug that interfers with DNA synthesis is an anti-B cell agent and include drugs like cyclophosphamide. This is because B cells divide more than T cells and as they kill dividing cells then B cells seem more susceptible. However they also kill activated dividing T cells. 

This study looks at Pixantrone an anti-cancer drug, and analogue of mitoxantrone with fewer toxic effects on heart tissue, that limit the number of times that mitoxantrone can be given. 

There were 4 treatments a month apart and the drug induced marked depletion of B cells and reduced gadolinium and the relapse rate.

Pixantrone acts as a topoisomerase II poison and intercalating agent and therefore the big question what is the risk of leukaemia, which is rather high following the use of mitoxantrone. 

As we now how to do trials in relapsing MS, one would probably find that if any of the old anti-cancer drugs that kill dividing cells that failed in secondary progressive MS, because the element of SPMS being examined is unresponsive to the drug, then they would work in relapsing SPMS and RRMS.

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