Mouse F(ab')2 IgG1 Lambda Isotype Control Antibody [PE]

Psoriasis is a common inflammatory skin disorder that requires chronic treatment and is associated with multiple comorbidities. Guselkumab, a human immunoglobulin-G1-lambda monoclonal antibody, binds to interleukin-23 with high specificity and affinity and is effective in treating moderate to severe plaque psoriasis. As part of the guselkumab psoriasis clinical trial program, using a confirmatory approach, a population pharmacokinetics (PopPK) model was established using 13014 PK samples from 1454 guselkumab-treated patients across 3 phase 2/3 trials. Observed serum guselkumab concentrations were adequately described by a 1-compartment linear PK model with first-order absorption and elimination. The final PK model was robust and stable, with apparent clearance (CL/F), apparent volume of distribution (V/F), and absorption rate constant (ka) estimates of 0.516L/day, 13.5L, and 1.11day(-1), respectively. A model-derived elimination half-life of 18.1days indicated achievement of steady-state serum guselkumab concentrations within 12-14 weeks. The primary covariate contributing to the observed PK variability was body weight, which accounted for only 28% (CL/F) and 32% (V/F) of the interindividual proportion of variance. Diabetes was identified to marginally reduce guselkumab exposure, owing to 12% higher CL/F in diabetic versus nondiabetic patients, but its contribution was not clinically relevant. None of the other covariates tested (eg, age, sex, ethnicity, immune response to guselkumab, or concomitant medications) had a clinically relevant effect on guselkumab exposure.

The tolerability, pharmacodynamic effects, and pharmacokinetics of belimumab (LymphoStat-B) were evaluated in cynomolgus monkeys. Belimumab is a fully human IgG1 lambda antibody directed against B-lymphocyte stimulator (BLyS) protein. BLyS is a TNF family member that supports B-lymphocyte maturation and survival and has been implicated in the pathogenesis of autoimmune diseases and B-lymphocyte malignancies. Belimumab was developed to antagonize BLyS activity in autoimmune diseases and B-lymphocyte malignancies, where undesirable effects of B-lymphocyte activity may cause or contribute to disease. Pharmacodynamic effects of belimumab were monitored by immunophenotyping of peripheral blood. Pathology end points, including tissue immunophenotyping, are described after 13 and 26 weeks of treatment and after a 34-week treatment-free (recovery) period. Belimumab was safe and well tolerated in repeat-dose toxicology studies at 5-50 mg/kg for up to 26 weeks. Monkeys exposed to belimumab had significant decreases in peripheral blood B lymphocytes by 13 weeks of exposure, continuing into the recovery period, despite total lymphocyte counts similar to the controls. There were concomitant decreases in spleen and lymph node B-lymphocyte representation after 13 or 26 weeks of treatment with belimumab. Microscopically, monkeys treated with belimumab for 13 or 26 weeks had decreases in the number and size of lymphoid follicles in the white pulp of the spleen. All findings were generally reversible within a 34-week recovery period. These data confirm the specific pharmacologic activity of belimumab in reducing B lymphocytes in the cynomolgus monkey. The favorable safety profile and lack of treatment-related infections also support continued clinical development of belimumab.