22. Dezember 2016

A new drug to treat two forms of multiple sclerosis

Considerable advances continue to be made in multiple sclerosis treatment. The latest data shows that the new drug ocrelizumab is clearly superior to the previously authorized drug interferon beta-1A in the treatment of relapsing-remitting multiple sclerosis. In addition, ocrelizumab is the very first drug to have an effect in the treatment of primary progressive multiple sclerosis and to delay the progression of disability. Results of the international phase 3 studies, which were conducted in part also at the University Hospital of Basel, have recently been published in the renowned New England Journal of Medicine.

 

Ocrelizumab is a newly developed humanized monoclonal antibody. The efficacy of ocrelizumab in two forms of multiple sclerosis (MS) was studied in phase 3 studies conducted in over 40 countries. Over 700 patients were included in the studies. Study participants with relapsing-remitting MS received 600 milligrams of ocrelizumab intravenously every 24 weeks and a placebo subcutaneously three times a week, or a placebo intravenously every 24 weeks and 44 micrograms of interferon beta-1A subcutaneously three times a week. In the study of primary progressive MS, the same dose of ocrelizumab or a placebo infusion was administered.

According to the now published study results, ocrelizumab reduced the number of relapses in relapsing-remitting MS by 45 percent as compared to interferon beta-1A, which is already available on the market. Moreover, magnetic resonance imaging showed that the number of inflammatory foci reduced by more than 90 percent. Since a lesser increase of disability caused by MS was also more likely with ocrelizumab, it can be considered as clearly superior to interferon beta-1A.

To date, there are no authorized effective therapies to treat primary progressive MS, which continuously progresses from the start without relapses. Ocrelizumab is now the very first drug to demonstrate significant effect as compared to placebo in a phase 3 study. Thus, it was found that further deterioration of the disability caused by MS was less likely with ocrelizumab.

A clearly more effective and well-tolerated therapy

The studies were headed by Prof. Ludwig Kappos of the University of Basel, Chief of Neurology at the University Hospital of Basel, Prof. Stephen Hauser of the University of California San Francisco, and Prof. Xavier Montalban of the Autonomous University of Barcelona. Prof. Kappos finds the results unequivocal: “Ocrelizumab is highly effective in relapsing-remitting MS and interferon beta-1A is clearly inferior. In primary progressive MS, ocrelizumab is the first drug to have an effect at all and delays the progression of disability.”

On the whole, ocrelizumab was well-tolerated in the now concluded phase 3 studies. Nevertheless, further studies of the long-term safety of this new therapy option are needed. The newly published results give reason to hope that a much more effective therapy will be available in the future to MS patients.

Along with the direct benefit for MS patients, the studies also contribute to a deeper understanding of the emergence of this disease. It has long been assumed that T cells are predominantly responsible for the inflammation and therefore for the progressing disability in MS. “Now, another subgroup of immune cells, the B cells, are increasingly at the center of interest as the driving force of inflammatory central nervous system disease,” says Prof. Tobias Derfuss, Head of the Neurology Polyclinic of the University Hospital of Basel. The monoclonal antibody ocrelizumab binds specifically to the CD20 receptor on the surface of B cells and leads to their complete disappearance from circulation. Together with his research group at the Department of Biomedicine, University of Basel, Derfuss is studying how B cells mistake the body’s own cells for foreign ones and react against them.