Low serum trough levels are associated with post-surgical recurrence in Crohn's disease patients undergoing prophylaxis with adalimumab

BACKGROUND: Whether therapeutic drug monitoring of biologic therapy can predict the efficacy of adalimumab to prevent postoperative Crohn's disease recurrence is unknown. AIM: To investigate whether adalimumab trough levels and anti-adalimumab antibodies correlate with endoscopic and clinical outcomes in a series of patients treated with prophylactic adalimumab monotherapy after resective surgery. METHODS: Post hoc analysis of a randomized, mesalamine-controlled trial. Adalimumab trough levels and antibodies were analysed every 8 weeks for 2 years using an homogeneous mobility shift assay. RESULTS: At two years, 1/6 patient had clinical recurrence and 1/6 patient had endoscopic and clinical recurrence. At baseline (9.5 vs. 14.4 mcg/mL) and during follow-up [7.5 (4.4-9.8) vs. 13.9 (8.9-23.6)mcg/mL, p<0.01], median adalimumab trough levels in patients with clinical or endoscopic recurrence were lower than in those who maintained remission. Persistent antibodies-against-adalimumab were detected in the patient with both endoscopic and clinical recurrence. CONCLUSION: Measurement of adalimumab trough levels and anti-adalimumab antibodies after surgery could be useful to further reduce postoperative recurrence.