Subcutaneous Absorption Contributes to Observed Interindividual Variability in Adalimumab Serum Concentrations in Crohn’s Disease: A Prospective Multicentre Study.
J Crohns Colitis. 2019 Mar 01;:
Authors: Casteele NV, Baert F, Bian S, Dreesen E, Compernolle G, Van Assche G, Ferrante M, Vermeire S, Gils A
BACKGROUND: Therapeutic drug monitoring is used to optimize adalimumab therapy in patients with Crohn’s disease (CD). However, the interindividual variability in drug absorption and the quantitative effect on drug clearance of antiadalimumab antibodies (AAA), measured with a drug resistant assay, is unclear.
AIM: Characterize adalimumab population pharmacokinetics (PopPK) and identify determinants of interindividual variability in patients with CD.
METHODS: Prospective multicentre open-label cohort study in 28 patients with CD starting adalimumab therapy. Peak, intermediate, and trough serum samples were analysed for adalimumab and AAA concentrations using a drug resistant assay. Adalimumab concentration-time data were analysed by non-linear mixed effects modelling and were adequately described by a PopPK model with first order absorption and one-compartment disposition with linear elimination. Clinical remission at week 12 (W12) was defined as a Harvey-Bradshaw index ≤4.
RESULTS: The absorption rate, volume of distribution, and clearance estimates of a typical patient were respectively 0.343 /day, 7.8 L, and 0.330 L/day. A 4-fold difference in the range of adalimumab concentrations was observed seven days after the first dose and found to be inversely correlated with baseline lean body weight (LBW), soluble tumour necrosis factor (s-TNF), and s-TNF receptor-1 whereas positive AAA and higher LBW were found to be important predictors of accelerated clearance. An adalimumab concentration at W12 of >7.3 µg/mL was significantly associated with achieving clinical remission at W12.
CONCLUSION: Variability in subcutaneous drug absorption is an important contributor to the observed interindividual variability in adalimumab concentrations, in addition to drug clearance. (ClinicalTrials.gov NCT02450513).
PMID: 30820530 [PubMed – as supplied by publisher]