Adalimumab Level and Anti-Drug Antibody for IBD, Serum

Comment

The American Gastroenterological Association recommends optimal adalimumab trough concentration of 7.5 mcg/mL or greater in patients with active IBD. Data from separate clinical studies suggest an optimal adalimumab trough concentration greater than 4.5 mcg/mL or 8-12 mcg/mL. Subtherapeutic adalimumab levels may be due to a patient not yet achieving a steady state trough level early in therapy, inadequate dosing, a dosing interval that is too long, or accelerated adalimumab clearance. Accelerated adalimumab clearance may be explained by the presence of adalimumab anti-drug antibody or rheumatoid factor in the patient's serum or may be caused by other diseases that indirectly lead to immunoglobulin loss (i.e., kidney disease, protein-losing gastroenteropathy).

• If adalimumab level is subtherapeutic but total adalimumab anti-drug antibody is not detected: Patients with a subtherapeutic adalimumab trough level, but no anti-drug antibody, may benefit from an increased adalimumab dose.
• If adalimumab level is subtherapeutic and total adalimumab anti-drug antibody is detected: Detectable serum adalimumab anti-drug antibody may cause accelerated adalimumab clearance leading to reduced trough levels and a compromised clinical response. Such patients are more likely to benefit from a switch in biologic therapy than from an increase in adalimumab dose.
• If adalimumab level is therapeutic and total adalimumab anti-drug antibody is not detected: In patients who do not respond or who lose their clinical response, mucosal inflammation is likely to be driven by a process that is not TNF alpha dependent. A switch to a different class of therapy should be considered.
• If adalimumab level is therapeutic and total adalimumab anti-drug antibody is detected: If the patient is responding clinically, the detected anti-drug antibody may not be clinically significant because the detected anti-drug antibody may not be functional or the level is inadequate to accelerate adalimumab clearance. Anti-drug antibody may disappear over time or increase, and, if increased, may cause subtherapeutic adalimumab levels and a loss of response in the future. Patients with a loss of adalimumab response despite therapeutic trough levels may benefit from a switch to a different class of therapy.

This information is provided for informational purposes only and is not intended as medical advice. A physician's test selection and interpretation, diagnosis, and patient management decisions should be based on his/her education, clinical expertise, and assessment of the patient.
The treating healthcare professional should refer to the manufacturer's approved labeling for prescribing, warnings, side effects and other important information.