A randomized, double-blind, three-arm, parallel group, single-dose phase I study to evaluate the pharmacokinetic similarity between SB12 (a proposed eculizumab biosimilar) and eculizumab (Soliris) in healthy subjects.

Objectives: To compare the pharmacokinetics (PK), pharmacodynamics (PD), safety, and immunogenicity between SB12 (a proposed eculizumab biosimilar) and the reference product (RP) eculizumab (i.e., European Union (EU)-sourced Soliris and United States (US)-sourced Soliris).

Materials And Methods: In this phase I study, healthy adult subjects were randomized to receive a 300-mg dose of SB12 or RP eculizumab via intravenous infusion. The PK endpoints were area under the serum concentration-time curve from time zero to infinity and to the last quantifiable concentration, and maximum serum concentration. Bioequivalence for the PK endpoints was determined if the 90% confidence intervals (CIs) for the ratio of geometric least squared means (Lsmeans) were within the pre-defined bioequivalence margins of 80.00 - 125.00%. PD, safety, and immunogenicity were also investigated.

Results: The 90% CIs of the geometric Lsmeans ratios of the PK endpoints were fully contained within the pre-defined bioequivalence margin. PD profiles and incidence of treatment-emergent adverse events across treatment groups were comparable. Incidence of anti-drug antibodies was also comparable between all groups, and a positive result for neutralizing antibodies was not detected.

Conclusion: This study demonstrated PK bioequivalence and similar PD, safety, and immunogenicity profiles of SB12 to both reference eculizumab products.