Secondary loss of response is often due to the development of anti-adalimumab antibodies (ATA), because of the immunogenic character of the drug. ATA can develop in any patient undergoing adalimumab therapy and are primarily neutralizing the activity of adalimumab through immunocomplex formation(3).
In addition, these immunocomplexes are rapidly cleared from the system(4).
Analytically, they are responsible for subtherapeutic adalimumab concentrations. Therefore, in the case of very low trough concentrations of adalimumab (< 1 μg/mL), subsequent measurement of ATA may be helpful to determine the optimal treatment strategy (5).