Originally Posted by pantos

"The participants developed more than three times as many brain lesions, or areas of damage in the brain that are a marker of MS disease activity, in the 15-month period after discontinuing the drug than they had developed before they started taking the drug. The results were most pronounced for those who took the drug for only a short time; they developed five times as many brain lesions after stopping the drug than they did before they started taking it."
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Vellinga said it’s not clear why discontinuing the drug would lead to increased disease activity, although an earlier animal study showed a similar result when rats with an animal model of multiple sclerosis were given a drug that suppresses the immune system.

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“All of our patients had an MRI shortly after the drug was suspended, and our neuroradiologist noticed that in some patients a considerable number of new lesions developed on their MRIs in the following year,” said Vellinga. “We decided to do a formal analysis to see if this was actually the case.” Vellinga noted that the results need to be confirmed in independent groups of patients.