Population Pharmacokinetics and Immunogenicity of Adalimumab in Adult Patients with Moderate-to-Severe Hidradenitis Suppurativa.

introductionHidradenitis suppurativa (HS) is a serious, debilitating, chronic inflammatory skin disease. Adalimumab is a fully human, immunoglobulin G1 monoclonal antibody specific for tumor necrosis factor-alpha recently approved for use in patients with HS. The aim of this study is to describe the population pharmacokinetics and immunogenicity of adalimumab in adult patients with HS.

methodsData from one phase II and two phase III studies were included in the analysis. Serial serum adalimumab concentrations and anti-adalimumab antibody (AAA) development status were used to develop the population pharmacokinetic model. The population pharmacokinetic analysis involved evaluating the effects of potential covariates on adalimumab pharmacokinetics.

resultsMean serum adalimumab concentrations after 40-mg weekly dosing reached steady state (10-12 µg/mL in the phase II study and 7 µg/mL in the phase III studies) by week 2 and were maintained through week 12. The percentage of patients testing positive for AAA was low (10% in the phase II study and 7% in the phase III studies). Adalimumab pharmacokinetics was described by a one-compartment model with first-order absorption. Significant covariates for clearance included the presence of AAA, baseline C-reactive protein, and baseline body weight.

conclusionsAdalimumab pharmacokinetics in HS patients was described using a one-compartment model with weight, baseline C-reactive protein, and AAA affecting adalimumab exposure. AAA development results in decreased adalimumab concentrations with a potential decrease in efficacy. Serum adalimumab concentrations in HS patients receiving 40-mg weekly dosing were similar to those observed in other indications under approved dosing regimens.