Antibodies to natalizumab may be commoner than previously reported. #MSBlog #MSResearch
Objectives: The purpose of this study is to monitor the development of anti-natalizumab antibodies to evaluate their first appearance in MSers, since their presence has been associated with a reduction in the efficacy of the treatment and an increase of adverse events.
Methods: A total of 134 MSers were included in the trial. Anti-natalizumab antibodies were monthly detected by ELISA up to the first year of treatment and subsequently, a determination was made at 18 months.
Results: 15.7 % of the MSers were positive, being 7.5 % transiently positive and 8.2 % persistently positive. The first appearance of anti-natalizumab antibodies occurred after the first month of treatment onset in 72 % of positive MSers; 18 % did so after the second month, and 9.7 % after the third month. Antibodies were never detected for the first time after the fourth infusion. The development of anti-natalizumab antibodies occurs very early after treatment onset.
Conclusion: These observations should be considered when standardizing the follow up of MSers treated with this drug in order to minimize the risks and optimize the treatment.
"Neutralizing anti-natalizumab antibodies stop the drug working and are associated with infusion reactions. We have noticed that a lot of units don't test for them routinely; they should. Why give an expensive drug to someone with antibodies when the drug won't work? They also are strongly associated with infusion reactions."