Ustekinumab (s) (Serum (s))

sample referred to a partner lab

both sex

There are currently no generally applicable therapeutic ranges for ustekinumab trough levels. Depending on the underlying disease, stage of treatment and therapeutic goal, the following threshold values can be recommended: Ustekinumab levels in Crohn's disease/ulcerative colitis: Post-induction (week 8): >= 3.5 µg/ml for remission Maintenance therapy: >= 1 µg/ml for remission and >= 4.5 µg/ml for mucosal healing The efficacy of therapy with ustekinumab depends, among other things, on the presence of anti-drug antibodies (ADA). In the absence of a clinical response, the following therapeutic decisions can be considered: Trough levels within the recommended range and no evidence of ADA: change outside of drug class. Trough levels below recommended range and evidence of ADA: Optimization of therapy interval/dose and immunomodulation or at higher ADA titers therapy switch within/of drug class. Papamichael K et al. Therapeutic drug monitoring in inflammatory bowel disease: for every patient and every drug? Curr Opin Gastroenterol. 2019 Apr 9.