Dr Shomron Ben-Horin and colleagues from Israel characterized the temporal evolution of antibodies to infliximab.
The research team performed a prospective observational study of infliximab-treated patients with inflammatory bowel disease between 2009 and 2012.
Trough levels of infliximab and antibodies to infliximab were measured before each infusion by anti-λ ELISA.
Patients were monitored for disease activity by clinical activity indexes and for dose-intensification or infliximab cessation.
The occurrence of transient antibodies to infliximab disappearing spontaneously without intervention was recorded separately.
|42% of patients remained antibodies to infliximab-free|
The team evaluated 125 patients, and 1119 sera were analyzed for infliximab and antibodies to infliximab levels.
Kaplan-Meier analysis showed that 42% of patients remained antibodies to infliximab-free by 4 years of treatment.
The researchers noted that most of the patients who developed antibodies to infliximab did so within the first 12 months of therapy, whereas transient antibodies to infliximab were detected throughout the duration of infliximab therapy.
Antibodies to infliximab incidence was similar between patients who received infliximab previously and scheduled-therapy patients.
In the scheduled group, combination immunomodulator+infliximab resulted in longer antibodies to infliximab-free survival compared with monotherapy.
The team noted that survival free of clinical loss of response was enjoyed by 51% of patients, and serial measurements showed that antibodies to infliximab development often preceded the onset of clinical flare.
Dr Ben-Horin's team concludes, "When followed prospectively, most patients who develop antibodies to infliximab do so within the first 12 months of therapy."
"This incidence is reduced by concomitant immunomodulator even in scheduled-therapy patients."
"In contrast, transient antibodies to infliximab, which are of little clinical significance, can appear haphazardly at any time during treatment."
"The onset of clinical loss of response may lag behind the appearance of anti-infliximab antibodies."