Why Does the Wearing-Off Phenomenon Happen?
Experts don’t know the answer to this yet. And there may be more than one reason. Because not all DMTs work in the same way, the reason for the wearing-off phenomenon may depend on the type of drug you’re taking.
Natalizumab, for example, prevents certain immune cells from getting into your central nervous system and causing damaging inflammation, says Dr. Gratch. But it blocks these cells for only about 8 weeks at a time before its effects begin to diminish. For that reason, patients typically receive infusions of natalizumab every 4 to 6 weeks. When spaced much further apart, you risk what’s called a rebound effect, in which your MS becomes active again, leading to symptoms and new lesions.
“It’s very well known and established that if you go about 8 to 12 weeks without getting natalizumab or switching [to another] DMT,
