Nakase H, et al. - This study was performed to assess the relationship of adalimumab trough levels and anti-adalimumab antibodies (AAA) at week 26 with clinical remission at week 52, the effect of azathiopurine on AAA and factors influencing trough levels in Crohn's disease (CD) patients in the DIAMOND trial. The researchers found a significant association between adalimumab trough levels and AAA occurrence with clinical remission. Higher 6-thioguanine nucleotide (TGN) affected AAA negativity. In some relevant aspects, the combination therapy was beneficial for CD patients.

• This study was performed by using adalimumab trough levels, AAA at week 26 and 6-thioguanine nucleotide (TGN) in red blood cells at week 12.
• The researchers performed a multiple regression model and receiver operating analysis to identify factors influencing adalimumab trough levels and AAA, and adalimumab thresholds for predicting disease activity.

• The researchers found a significant difference of adalimumab trough level at week 26 between patients with disease remission and without at week 52 (7.7 ± 3.3 μg/mL vs 5.4 ± 4.3 μg/mL: P <.001).
• For remission prediction, adalimumab trough level of 5.0 μg/mL yielded optimal sensitivity and specificity (80.2% and 55.6%, respectively).
• At week 26, AAA development significantly influenced remission at week 52 (P = .021), which was strongly correlated with adalimumab trough levels.
• Factors independently associated with low adalimumab trough levels were female gender and increasing body weight, and female gender was correlated with AAA developmentt.
• As per the outcomes, a cut-off 6TGN level of >222.5 p mol/8 ×10⁸ RBCs yielded sensitivity (100%) and specificity (60.6%) for AAA negativity.