Exposure-response relationship of certolizumab pegol induction and maintenance therapy in patients with Crohn's disease.

Abstract

SummaryBackgroundTherapeutic drug monitoring may optimize therapy for Crohn's disease (CD).AimTo use a population pharmacokinetic model that accounts for the time‐varying nature of covariates to simulate certolizumab pegol (CZP) concentrations to evaluate the exposure‐response relationship for CZP in Crohn's disease.MethodsAdults (N = 2157) with Crohn's disease were treated with CZP in nine clinical trials. Simulated CZP concentrations were compared to outcomes at weeks 6 and 26, including Crohn's disease activity index (CDAI) response (decrease from baseline ≥ 100 points), remission (CDAI ≤ 150), C‐reactive protein (CRP) ≤ 5 mg/L, faecal calprotectin (FC) ≤ 250 μg/g, and a composite endpoint of CDAI ≤ 150 and FC ≤ 250 μg/g. Multivariable analyses identified covariates associated with outcomes and receiver operating characteristic analyses determined optimal CZP concentrations.Results CZP concentrations at weeks 2, 4 and 6 were higher in patients with clinical response, remission, CRP ≤ 5 mg/L or FC ≤ 250 μg/g at week 6 than without. In multivariable analyses, higher CZP concentrations at week 6 were associated with the composite outcome at weeks 6 and 26 (P < .001). Although the exposure‐response relationship varied among patients, approximate CZP concentrations of at least 36.1 μg/mL (positive predictive value [PPV] 22.8% and negative predictive value [NPV] 92.7%) and at least 14.8 μg/mL (PPV 28.0% and NPV 90.4%) at weeks 6 and 12 were associated with weeks 6 and 26 outcomes.ConclusionsAn exposure‐response relationship was apparent for CZP in Crohn's disease and achieving higher CZP concentrations may increase the likelihood of attaining efficacy outcomes, but this remains to be evaluated prospectively.