Treatment of progressive MS – are we any closer?

Abstract

Over the last twenty years, Multiple Sclerosis (MS) has moved from being an untreatable condition, with few therapeutic options to a position of active management underpinned by a range of oral and injectable treatments. These advances however are restricted to patients with the relapsing/remitting form of MS (RRMS), while for those with the progressive forms of the condition there are virtually no treatments available. These patients constitute over 50% of the 2.3 million people with MS worldwide and addressing their needs is all the more important as progression is the main determinant of disability in MS and carries the greatest economic burden. The reasons behind this therapeutic vacuum include (1) poor understanding of the mechanisms underlying neurodegeneration and the identification of potential treatment targets (2) lack of clarity in defining the progressive phenotype (3) developing appropriate trial design with effective biomarkers and clinical outcomes (4) the need for improved symptom management and rehabilitation. A number of initiatives have emerged including the International Progressive MS Alliance (PMSA), which has united MS Societies and clinical academics worldwide. We are now seeing important insights into pathological mechanisms, greater clarity over clinical phenotypes and innovative trial designs. Results from clinical trials have been mixed, with some cause for optimism. However, the imminent outcome from several major studies has the potential to change the direction of travel irrevocably. If we are to have the same impact on progressive MS as seen in RRMS, we will need a focused, global and consistent approach going forward.