Dr Gordon Greenberg from Canada assessed the effect of infliximab infused at scheduled intervals on antibody formation in Crohn's.
The investigative team evaluated antibodies to infliximab and trough serum infliximab in 105 patients with Crohn's.
In Group 1, 23 patients were treated with 5 mg/kg infliximab for induction followed by maintenance episodic re-treatment.
Group 2 included 82 patients receiving scheduled therapy at 6- to 8-week intervals.
|Antibody formation modulates serum infliximab|
|Clinical Gastroenterology & Hepatology|
After a median of 14 infusions, 21% of patients had detectable antibodies, 25% were antibody negative, and 54% were antibody inconclusive.
The investigators found that antibody formation was higher after episodic compared with scheduled treatment.
The team noted that antibody formation was associated with a higher rate of infusion reactions.
The investigators identified 90 patients that continued maintenance scheduled therapy beyond 12 months including 12 converted episodic patients.
The rate of clinical remission was higher for patients with a detectable trough serum infliximab vs those in whom serum infliximab was undetectable.
The team observed that the rate of clinical remission was lower in patients without antibodies.
A detectable trough serum infliximab was also associated with a lower C-reactive protein.
The investigative team found that trough serum infliximab was associated with a higher rate of endoscopic improvement.
Concurrent immunomodulators did not alter outcomes.
Dr Greenberg's comments, “For Crohn's disease patients treated with scheduled maintenance infusions of infliximab, the trough serum concentration of infliximab predicts clinical outcome.”
“Factors in addition to antibody formation, likely pharmacokinetic, modulate serum infliximab and thus the response to infliximab therapy.”