Pharmacokinetics and Safety of Spesolimab in Healthy Chinese Subjects: An Open-Label, Phase I Study

Introduction: Generalized pustular psoriasis (GPP) is a rare and potentially life-threatening inflammatory skin disease. Interleukin (IL)-36 signalling may play a central role in GPP pathogenesis. Spesolimab is a humanized anti-IL-36 monoclonal antibody inhibiting the IL-36 signalling pathway. Here, we investigated the pharmacokinetics and safety of spesolimab in healthy Chinese subjects.

Methods: In this Phase 1, single-dose, parallel-group, open-label study, healthy Chinese subjects aged 18-45 years received a single spesolimab dose by intravenous infusion (IV; 450 mg, 900 mg, or 1200 mg) or subcutaneous (SC) administration (300 mg or 600 mg). Primary endpoints were spesolimab exposure (area under the plasma concentration-time curve and maximum plasma concentration); secondary endpoints were treatment-emergent adverse events (TEAEs) and drug-related adverse events (AEs).

Results: Fifty subjects received IV (n = 30) or SC (n = 20) spesolimab (n = 10 per dose group); 60.0% were male, mean ± standard deviation age was 31.5 ± 6.6 and 31.0 ± 6.5 years in the IV and SC groups, respectively. Spesolimab exposure increased in a dose-proportional manner in both groups. TEAEs were reported in 83.3% and 80.0% of subjects in the IV and SC groups, the most common TEAE was upper respiratory tract infection (20.0% and 25.0%, respectively). One serious AE of hand fracture was reported in the 900 mg IV group that was not considered drug-related. Drug-related AEs were reported in 53.3% and 55.0% of subjects in the IV and SC groups. All laboratory-related AEs were mild and resolved.

Conclusion: Spesolimab exposure increased in a dose-proportional manner after a single dose by IV and SC administration. Spesolimab was well tolerated in healthy Chinese subjects.

Clinical trial registration: Clinicaltrials.gov registration: NCT04390568.