Monitoring the concentration of TNF-α inhibitor drugs and the development of anti-drug antibodies (ADA) enables physicians to optimize patient treatment over time. The test results help physicians understand underlying causes of suboptimal outcomes, make informed therapy choices, and provide more effective treatment to their patients. The use of TNF-α inhibitors has revolutionized the treatment of patients with several non-infectious inflammatory disorders, including Crohn disease and ulcerative colitis.
There is currently no established standard for handling patients with treatment failure to TNF-α inhibitors. One approach is to monitor drug levels and anti-drug antibodies. Current methods for ADA detection are complicated by the fact that most TNF-α inhibitors are antibodies and by the complexity of measuring antibodies against antibodies in non-functional binding assays. More importantly, all non-ARUP methods fail to differentiate binding from neutralizing ADA.
ARUP’s TNF-α activity and neutralizing antibody assays are cell-based bioassays that measure the ability of a drug to inhibit TNF-α. The assays also detect the presence of antibodies that neutralize drug activity. Emergence of these neutralizing antibodies in a patient leads to treatment failure. Other methods measure drug and drug antibodies that bind to infliximab or Adalimumab. Unlike ARUP’s assays, these methods cannot distinguish whether the antibodies neutralize drug activity or not.