A randomized trial comparing LY01011, biosimilar candidate, with the reference product denosumab (Xgeva®) in healthy Chinese subjects

Background: Complications of bone metastases such as skeletal-related events lead to the impaired functional status and quality of life including death in patients with bone metastasis from solid tumors. Denosumab (XGEVA®) is indicated for the prevention of skeletal-related events in bone metastasis patients with solid tumors. The biosimilar product LY01011, a fully human anti-receptor activator of nuclear factor kappa-B ligand monoclonal antibody, was developed to be compared with the reference product denosumab. Material and methods: A randomized, double-blind, single-dose, parallel-controlled phase 1 study was conducted in healthy Chinese subjects. A total of 168 enrolled subjects were randomly assigned in a 1:1 ratio to receive a single 120 mg dose of LY01011 (n = 85) or denosumab (n = 83) subcutaneously. The primary pharmacokinetic (PK) parameters, including maximum plasma concentration (Cmax) and area under the concentration–time curve from time zero to last quantifiable concentration (AUC0→t), were collected and measured for evaluation. Other secondary PK parameters included AUC0- ∞, Tmax, CL/F, λz, t1/2, Vd/F, etc. Pharmacodynamics (PD), safety and immunogenicity profiles were also accounted for data analysis. Results: The geometric mean ratios (GMRs) of LY01011 and denosumab for the primary PK parameters such as Cmax and AUC0→t were 98.13% and 100.32%. The 90% confidence intervals (CIs) were all within the acceptance range of 80%-125%. The GMRs of the PD parameters including AUEC0→t and Emax were 98.71% and 99.80%, which fell within the pre-defined acceptance range of 80%-125%. The results also demonstrated PK similarity even if Cmax and AUC0→∞ had been used as primary endpoints. Safety profiles were tolerable and similar between groups. 4 (4.7%) and 2 (2.4%) subjects had experienced Grade 3 or above treatment-emergent adverse events (TEAEs) in LY01011 group and denosumab group. 3 subjects were reported to have serious adverse events (SAEs). None of the Grade 3 or above TEAEs and SAEs were related to the study drug, LY01011. No subject was tested anti-drug antibody (ADA) positive in both groups prior to the study drug administration. Following the study drug administration, only one subject in denosumab group was tested ADA positive, whereas no subject with ADA positive was reported in LY01011 group. No neutralizing antibody (Nab) was detected in either group throughout the study. Conclusions: The study demonstrated PK and PD similarity of LY01011, a denosumab biosimilar, to denosumab in healthy Chinese subjects, with comparable safety and immunogenicity profiles.