BACKGROUND AND OBJECTIVELY01008 had been identified as being highly similar to the bevacizumab reference product in the pharmacy and pharmacology terms. The primary objective of this study was to compare the pharmacokinetic characteristics of the biosimilar candidate LY01008 with that of the bevacizumab (Avastin®) reference product after a single intravenous infusion in healthy Chinese adults. The secondary objective was to compare the safety and immunogenicity of LY01008 with those of bevacizumab.METHODSIn this double-blind, parallel-group, phase I study, 102 male subjects aged 18-45 years were randomized 1:1 to receive a single intravenous infusion of 3 mg/kg LY01008 or bevacizumab. Before the pivotal section, 12 healthy male subjects receiving a single intravenous (IV) infusion of 0.5 mg/kg or 1.5 mg/kg LY01008 were screened to verify the safety and tolerability of LY01008. Primary endpoints included the area under the concentration-time curve (AUC) from time zero to the last quantifiable time point (AUC0-t), AUC from time zero to the infinity time (AUC0-inf), and maximum plasma concentration (Cmax).RESULTSThe geometric mean ratios (GMRs) (90% confidence intervals, CIs) of AUC0-t, AUC0-inf, and Cmax of LY01008 to bevacizumab were 87.62% (82.91%, 92.61%), 87.27% (82.46%, 92.35%), and 96.45% (91.37%, 101.81%), respectively, in the pivotal section, which were within the prespecified equivalence margin of 80.00-125.00%. LY01008 and bevacizumab administered as a single 3 mg/kg intravenous dose were comparably well tolerated. No new or unexpected adverse events were observed. Nine subjects had antidrug antibodies (ADAs) (5 in the LY01008 group and 4 in the bevacizumab group) after dosing. No neutralizing antibody (Nab) was detected.CONCLUSIONLY01008, a recombinant humanized monoclonal antibody (mAb) against vascular endothelial growth factor (VEGF), displayed pharmacokinetic similarity to bevacizumab, and good safety and tolerability profiles. The data from this trial provide fundamental information for further development.TRIAL REGISTRATIONClinical trial registration ID: CTR20170191.