C5aR1 antagonist 2 (Compound 6a), an orally active antagonist of C5a receptor 1 (C5aR1), effectively inhibits increases in neutrophil counts induced by C5a. This compound demonstrates potency in both DISCO and migration assays, with IC50 values of 21 and 3 nM, respectively. It is utilized in the study of acute and chronic inflammatory diseases [1].

C5aR1 antagonist 2 在剂量为1至10 mg/kg, 口服方式下, 能显著地抑制 C5a 诱导的 CD11b 上调，并完全显示出剂量依赖性抑制效果。此外，该药物在 Sprague−Dawley 雌性 hC5aR1 敲除大鼠模型中，同样能抑制由 C5a 诱导的中性粒细胞增多。药代动力学分析显示，在口服10 mg/kg的剂量下，AUC 0-last 为35700 ng·h/mL，C max 为3610 ng/mL，T max 为2.5 h，CL 为39 mL/(min*kg)，V ss_obs 为7.1 L/kg，t 1/2 为3.7 h。