Multiple sclerosis is a disease measured by “flares,” or a period when symptoms get worse (flare up). Each time there’s a flare, the disease has progressed–irreversibly. Many doctors are wary of early, or induction therapy, which is considered “aggressive” and can have side effects that are worse than the actual flares. But this ad, seeding the market for a new induction therapy, flames the debate about when to treat MS to get doctors thinking about the risks of waiting.