Population Pharmacokinetics and Exposure-Response Modeling Analyses of Golimumab in Children With Moderately to Severely Active Ulcerative Colitis

Population pharmacokinetics (PK) and exposure-response (E-R) analyses were conducted to compare the PK and E-R relationships of golimumab between children and adults with ulcerative colitis. PK data following subcutaneous golimumab administration to children with ulcerative colitis (6-17 years) in the PURSUIT-PEDS-PK study, adults with ulcerative colitis in the PURSUIT study, and children with pediatric polyarticular juvenile idiopathic arthritis (2-17 years) in the GO-KIDS study, were included in the population PK analysis. E-R analysis was conducted using logistic regression to link serum golimumab concentration and Mayo score–based efficacy outcomes in pediatric and adult ulcerative colitis. Golimumab PK was adequately described by a 1-compartment model with first-order absorption and elimination. Golimumab apparent clearance and volume of distribution increased with body weight. Golimumab apparent clearance was higher in patients with lower serum albumin, no methotrexate use, and positive antibodies to golimumab; age was not an influential factor after accounting for body weight. Model-estimated terminal half-life (9.2 days in children; 9.5 days in adults) and other PK parameters suggest that golimumab PK properties are generally comparable between children and adults with ulcerative colitis. Simulations suggest that a higher induction dose than that tested in PURSUIT-PEDS-PK may be needed for children ≤45 kg to achieve exposures comparable to adults. Comparable E-R relationships between children and adults with ulcerative colitis were observed, although children appeared to be more responsive for the more stringent remission end point. The overall comparable PK and E-R relationships between children and adults support the extrapolation of golimumab efficacy from the adult to the pediatric ulcerative colitis population.