Watanabe K, et al. - The researchers assessed factors correlated with endoscopic response and mucosal healing in study participants. They found that adalimumab in combination with azathioprine increased trough levels of adalimumab. At weeks 26 and 52, higher trough levels of adalimumab correlated with endoscopic response and mucosal healing.

• From June 2011 to June 2014, the researchers compared simple endoscopic scores for CD (SES-CD) in between patients with moderate to severe active CD randomly assigned groups that received adalimumab monotherapy (n=85) or adalimumab in combination with azathioprine (n=91) in Japan.
• In this study, they assessed associations SES-CD with clinical factors and trough levels of adalimumab.
• Finally, they examined 135 patients at week 26 and 139 patients at week 52 from 44 referral sites for the present investigation.

• In the combination group, the odds for endoscopic response was significantly higher than in the monotherapy group at week 26 (odds ratio [OR], 2.12; 95% CI 1.04-4.32) but not at week 52 (OR,1.50; 95% CI, 0.77-2.94).
• At weeks 26 or 52, the odds of mucosal healing did not differ significantly between groups.
• In this study, SES-CD at week 0 was significantly correlated with mucosal healing at week 26 (OR, 0.80; 95% CI, 0.72-0.90) and at week 52 (OR, 0.91; 95% CI, 0.84-0.99).
• Higher adalimumab trough level at week 26 correlated with mucosal healing at week 52 (OR, 1.34; 95% CI 1.14-1.58; P for trend=.001).
• In patients with endoscopic response, this adalimumab trough level was significantly higher than in patients without endoscopic response at week 26 and 52 (P < .001).