ABSTRACT
The past 15 years have been a remarkably productive period for clinical trials in multiple sclerosis (MS). Five new therapeutic agents, representing three different classes of drugs, have been approved for use throughout most of the world, targeting relapsing forms of MS, secondary progressive disease and ‘worsening’ disease, depending on the countryspecific regulatory approvals. At the time of this writing, pivotal studies on primary progressive disease and on new classes of agents are under way. Earlier-phase studies of promising new agents have been undertaken, some of which are destined to move to larger-scale, multicenter, pivotal studies. Some preliminary studies, as well as some larger, pivotal trials, have failed or have provided difficult-to-interpret results.
