Population pharmacokinetic/target engagement modelling of tozorakimab in healthy volunteers and patients with chronic obstructive pulmonary disease.

Aims: This study describes the pharmacokinetic (PK)/target engagement (TE) relationship of tozorakimab, an anti‐interleukin (IL)‐33 antibody, by building a mechanistic population PK/TE model using phase 1 biomarker data. Methods: The analysis included tozorakimab PK and TE in serum assessed in 60 tozorakimab‐treated participants, including healthy adults and patients with mild chronic obstructive pulmonary disease. Scenarios evaluated three dose frequencies (once every 2, 4 or 6 weeks) administered subcutaneously at seven doses of tozorakimab (30, 60, 90, 120, 150, 300 or 600 mg). For each dose, simulations were performed with 5000 virtual individuals to predict systemic TE. Inhibition of IL‐33/soluble ST2 (sST2) complex levels at trough PK at steady state was assessed in each dosing scenario. The PK/TE modelling analyses were performed using a nonlinear mixed‐effect modelling approach. Results: The final two‐compartment PK model with tozorakimab binding IL‐33 in the central compartment adequately described the systemic PK and TE of tozorakimab at population and individual levels. The mean PK parameter estimates of absorption rate, central volume of distribution and clearance were 0.48 (90% confidence interval [CI]: 0.40–0.59, 1/day), 12.64 (90% CI: 8.60–18.62, L) and 0.87 (90% CI: 0.65–1.16, L/day), respectively. Consistent with the observed value, tozorakimab bioavailability was 45%. For all three dose frequencies, predicted inhibition of systemic IL‐33/sST2 levels was more than 95% at doses greater than 90 mg. Conclusions: The PK/TE model reliably quantified the relationship between PK and systemic TE of tozorakimab, with potential utility for predicting clinical dose–response relationships and supporting clinical dose selection. [ABSTRACT FROM AUTHOR]