Seventy-five people were randomly assigned to either Betaseron or Copaxone and monitored for two years with monthly MRIs. Basically, in both groups roughly a quarter of people had no active lesions during the study, half had "episodic" lesions, and a quarter had "frequent" lesions.
The study, presented at the Consortium of Multiple Sclerosis Centers annual meeting on June 1st, was funded by Berlex, the makers of Betaseron, who must have thought that Betaseron would beat Copaxone for effectiveness.
Another finding of the study was that the people with the frequent lesions performed worse on cognitive and behavioral/physical tests (which seems pretty logical to me). However, this sensitive monitoring of lesions is not done in clinical settings and subtle impairments may go unnoticed by physicians. David Cadavid, the lead investigator of the study, said of the people with frequent lesions, "...they seem to carry some loss of function when you first see them. Even though you put them on the drug, you are not really controlling them. They're getting disabled in front of you." He said that these are the people that should be targeted to use the more powerful new drugs, even with the higher risk profile.