Pharmacokinetics, Pharmacodynamics, Safety, and Tolerability of <scp>HSK39297</scp> in Chinese Healthy Subjects: A Phase 1 Clinical Trial

HSK39297 is a novel complement factor B inhibitor, and this phase 1 trial was designed to assess its pharmacokinetics (PK), pharmacodynamics (PD), safety, and tolerability in healthy Chinese subjects. This study included 46 subjects in the single ascending dose (SAD) part (50-600 mg) and 50 subjects in the multiple ascending dose (MAD) part (50-125 mg BID and 200-300 mg QD). Among them, a food effect study was conducted in the SAD 200 mg group. Adverse events (AEs) reported after the initial dose of the study drug were considered treatment-emergent AEs (TEAEs). Blood samples were collected to measure plasma concentrations of HSK39297 at predefined time points and analyzed at a centralized laboratory. In addition, PD analysis was conducted by measuring complement alternative pathway (AP) activity and Bb concentrations. According to the results, we found single and multiple doses of HSK39297 were safe and well tolerated in all subjects. Within SAD of 50-600 mg dose range, the C_max, AUC_0-t, and AUC_0-∞ exhibited nonlinear PK characteristics. The high-fat meals did not significantly affect the absorption rate and systemic exposure levels of HSK39297, and GMRs for fed versus fasting states were 108.05% (99.66%, 117.15%), 98.73% (89.34%, 109.09%), and 97.86% (84.66%, 113.11%), respectively. In MAD part, dose-drug exposure showed a linear relationship. PD analysis indicated that oral administration of HSK39297 tablets resulted in dose-dependent inhibition of the AP activity and Bb concentration. These findings support advancing HSK39297 into later-phase trials for complement-mediated glomerular diseases.