Effect of Therapeutic Drug Monitoring vs Standard Therapy During Maintenance Infliximab Therapy on Disease Control in Patients With Immune-Mediated Inflammatory Diseases

SPS commentary:

According to an editorial, many patients on biologics do not respond to treatment, and approximately 50% of initial responders subsequently have inadequate disease control, defined as secondary failure. Causes are poorly understood. Antidrug antibodies and low drug concentrations are likely important contributors to secondary failure. Low drug concentrations may contribute to antidrug antibody formation. It notes the relatively large sample size and rigorous study design of this study helped to overcome some limitations of previous observational studies and small clinical trials that yielded conflicting results regarding TDM. Findings were in contrast to the results of another randomized clinical trial by the same research group (the NOR-DRUM A trial), which demonstrated no benefit of TDM for remission induction compared with standard care among 411 patients with inflammatory-mediated diseases initiating infliximab therapy (rates of remission, 100/198 [50.5%] vs 106/200 [53.0%], respectively). It adds that it is not clear whether these results may apply to other bDMARDs because infliximab may be particularly prone to antidrug antibodies, with other medications such as methotrexate often recommended to protect against infliximab antibody development. It calls for further study to determine whether TDM may be effective for patients with other conditions and for other bDMARDs.