PF-06881894, a Proposed Biosimilar to Pegfilgrastim, Versus US-Licensed and EU-Approved Pegfilgrastim Reference Products (Neulasta): Pharmacodynamics, Pharmacokinetics, Immunogenicity, and Safety of Single or Multiple Subcutaneous Doses in Healthy Volunteers.

Introduction: PF-06881894 is a proposed biosimilar to pegfilgrastim (Neulasta). This study evaluated the pharmacodynamic/pharmacokinetic (PD/PK) equivalence, immunogenicity, and safety of PF-06881894 vs pegfilgrastim reference products (US- and EU-Neulasta) in healthy volunteers.

Methods: A phase 1, open-label, randomized, crossover study was conducted to assess the pharmacologic equivalence and safety of a single 6-mg dose of PF-06881894, pegfilgrastim-US, and pegfilgrastim-EU. The primary PD endpoints were area under the effect-versus-time curve for absolute neutrophil count (ANC) from dose administration to 288 h postdose, and maximum observed ANC value among subjects confirmed negative for anti-pegfilgrastim antibodies. Primary PK variables included area under the serum pegfilgrastim-versus-time curve from the time of dose administration to time infinity and maximum observed serum pegfilgrastim concentration. A second phase 1, open-label, randomized (1:1), parallel-group, non-inferiority study was conducted to assess the immunogenicity and safety of multiple 6-mg doses of PF-06881894 versus pegfilgrastim-US. The primary endpoint for the immunogenicity study was the proportion of subjects with both negative baseline and confirmed positive postdose anti-pegfilgrastim antibodies at any time during the study.

Results: Across the single- and multiple-dose studies (N = 153 and N = 420 treated subjects, respectively), demographics for age (18-65 years), male gender (n = 264/573), and white race (n = 423/573) were similar. Three-way PD/PK equivalence of PF-06881894, pegfilgrastim-US, and pegfilgrastim-EU was demonstrated with the primary PD endpoints and primary PK variables being completely contained within the predefined 90% confidence interval acceptance limits (80-125%). The non-inferiority of PF-06881894 versus pegfilgrastim-US in terms of immunogenicity was established according to the prespecified non-inferiority margin (≤10%). Overall, there were no clinically meaningful differences in safety profiles among or between study groups.

Conclusions: Single-dose PF-06881894 demonstrated PD/PK equivalence and comparable safety with US- and EU-pegfilgrastim reference products. Multiple-dose PF-06881894 demonstrated immunogenicity non-inferiority to pegfilgrastim-US with comparable safety. Both studies contributed to the totality of evidence supporting biosimilarity.

Trial Registration: ClinicalTrials.gov identifiers: NCT02629289; NCT03273842 (C1221005).