The effect of scheduled antibody testing on treatment patterns in interferon-treated patients with multiple sclerosis.
BACKGROUND
Many patients with relapsing-remitting multiple sclerosis (MS) treated with high-dose interferon-β (IFNβ) develop serum binding antibodies (BAb) and neutralizing antibodies (NAb). NAb reduces the biological activity of IFNβ, which contributes to clinical failure in these patients. We investigated whether access to antibody (Ab) test results would alter usual care of (IFNβ)-treated patients and whether BAb could predict NAb.


METHODS
This was a randomized, controlled, open-label, parallel-group, multicenter study in patients with multiple sclerosis. Subjects (n = 1358) were randomly assigned to Ab testing or usual care. BAb and NAb titres were measured using standard assays. Primary and secondary outcomes were the proportion of patients whose IFNβ therapy changed and the type of and reasons for therapy changes.


RESULTS
Therapy changes differed between the Ab testing and usual care arms (19.6% and 14.0%, respectively; p = 0 · 004). Results from Ab testing were more frequently reported as the reason for therapy change in the Ab testing arm than in the usual care arm (p < 0.0001). NAb and BAb positivity significantly increased the likelihood of therapy change and reduced IFNβ-associated adverse events. BAb titres were a significant predictor of NAb positivity (p = 0.0012). Initial BAb-positive and NAb-positive status in both study arms had a significant impact on the overall number of patients with a therapy change (p < 0.05).


CONCLUSIONS
Access to Ab test results impacted therapy management. BAb titres can predict NAb positivity in patients on high-dose IFNβ.
Central Texas Neurology Consultants, 16040 Park Valley Drive, Suite 100, Round Rock, TX 78681, USA. foxtexms@gmail.com.
Edward
E
Fox
Barbara
B
Green
Clyde
C
Markowitz
Ronald
R
Murray
Andrew D
AD
Goodman
Stephen J
SJ
Glenski
Pippa
P
Loupe
Jo Nita
JN
Cogburn
D000328:Adult; D057134:Antibodies, Neutralizing / Q000097:blood* / Q000276:immunology; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use*; D016899:Interferon-beta / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000097:blood* / Q000188:drug therapy* / Q000276:immunology; D010818:Practice Patterns, Physicians'
D057134:Antibodies, Neutralizing; D007155:Immunologic Factors; D016899:Interferon-beta