The article discusses the design and results of recently published study of an analog of the original glatiramer acetate. The necessity of the correct planning and analysis of the data of such studies is stressed, showing equal efficacy, tolerability and safety of analog and original drug. The optimal design of such studies, their duration, selection of primary endpoint, adequate assessment of clinical and MRI changes and side-effects are discussed. The authors reckon that it is impossible to plan studies the results of which are based on the design, i.e. the absence of differences from the original drug. The authors invite specialists in MS to participate in the discussion.