A method for treating a human subject afflicted with multiple sclerosis or a single clinical attack consistent with multiple sclerosis with a pharmaceutical composition comprising glatiramer acetate and a pharmaceutically acceptable carrier, comprising the steps of determining whether the human subject is a glatiramer acetate responder by evaluating a biomarker selected from the group consisting of IL-17 concentration, TNF-a concentration, IL-2 concentration and IFN-γ concentration, or a combination thereof, in the blood of the human subject and administering the pharmaceutical composition comprising glatiramer acetate and a pharmaceutically acceptable carrier to the human subject only if the human subject is identified as a glatiramer acetate responder.