Pharmacokinetics, Safety, Tolerability, and Immunogenicity of BP02 (Trastuzumab Biosimilar) Compared to EU- and US-Approved Trastuzumab in Healthy Adult Male Volunteers: A Phase 1, Randomized, Double-Blind Study

IntroductionThis study evaluated the pharmacokinetic (PK) equivalence between BP02 (a proposed trastuzumab biosimilar) and the reference trastuzumab approved in the EU (EU-trastuzumab) and the US (US-trastuzumab).MethodsIn this phase 1, double-blind, parallel-group trial, 111 healthy male volunteers were randomized 1:1:1 to receive a single 6-mg/kg intravenous infusion of BP02, EU-trastuzumab, or US-trastuzumab and were evaluated for 78 days. Serum drug concentration-time data were analyzed by non-compartmental methods. The PK similarity of BP02 to the two reference products, and between EU-trastuzumab and US-trastuzumab, was determined using the standard 80-125% bioequivalence criteria.ResultsBaseline demographics for the 111 subjects with evaluable pharmacokinetics were similar across all treatment groups. PK profiles were similar for the three products. The 90% confidence intervals (CIs) for the ratios of area under the serum concentration-time curve (AUC) from the time of dosing to infinity (AUC0-inf), AUC from the time of dosing until the time of the last quantifiable concentration (AUC0-t), and peak serum concentration of trastuzumab (Cmax) were within 80% to 125% for all three pairwise comparisons. Adverse events (AEs) were similar across all arms, with treatment-related AEs reported by 73.0%, 73.0%, and 89.2% of the subjects in the BP02, EU-trastuzumab, and US-trastuzumab groups, respectively. The most common AEs were headache, infusion-related reactions, and upper-respiratory-tract infections. Four subjects-three in the US-trastuzumab group and one in the BP02 group-discontinued the study due to AEs. All post-dose samples except for two tested negative for anti-drug antibodies.ConclusionThis study demonstrates the PK similarity among BP02, EU-trastuzumab, and US-trastuzumab. The safety and immunogenicity profiles observed for the three products in this study are consistent with previous reports for trastuzumab.Trial RegistrationANZCTR number: ACTRN12621000573853.