Overview of Sphingosine 1-Phosphate (S1P) Receptor Modulators

Stephen Krieger, MD: Let’s turn to a second topic in MS [multiple sclerosis] treatment. We are very lucky to have not only a broad array of medicines, but now second, and in some cases third, generations of the drugs that we have, which is a wonderful problem. But it gives us an opportunity to parse some of the nuances of our treatments. There was a time not that long ago when we had 1 pill for multiple sclerosis, when fingolimod was approved back in 2010. A dozen years later, we now have several different medicines in that class. So fingolimod spawned the subsequent S1P [sphingosine-1-phosphate receptor] modulators: siponimod, ozanimod, and ponesimod. Let’s think about how we parse between them a bit. What are some fundamental differences between, let’s call it old school S1P modulators, fingolimod, and this newer generation? Dr Crayton, how would you broadly describe it?