Not something to worry about, just something to be aware of. It is the last 2 or 3 sentences of the abstract (below) to internalise and raise with your Neuro.
At the population level this enables the drug to work in most pwMS, but in some individuals level, as we show here, antibody neutralization appears to be sufficiently severe to reduce efficacy and allow disease-breakthrough. It is therefore imperative that efficacy of lymphocyte depletion and the anti-drug response is monitored in people requiring additional cycles of treatment, notably following disease breakthrough. This may help inform whether to re-treat or switch to another disease modifying treatment.