Dew- See page 9 of the transcript of the call. No mention of Tysbri during, before, or after the question. Just "the competiton". Again, Tysabri is primarily 2nd line. Copaxone is 1st line. Its primary competition are the interferons which are also 1st line.
Most (not all) Tysabri patients have failed Copaxone and the interferons.