Table 2.
Summary of Pegfilgrastim PK Parameters Following a Fixed Single Subcutaneous Injection of 6 mg of Proposed Pegfilgrastim Biosimilar or Pegfilgrastim Reference Product to Healthy Subjects (PK Population)a
| Proposed Pegfilgrastim | Pegfilgrastim Reference | |||
|---|---|---|---|---|
| Biosimilar, Arithmetic | Product, Arithmetic | Relative Meanb | ||
| PK Parameter | Mean (SD), n = 56 | Mean (SD), n = 56 | Ratio, % | 90%CI |
| AUCt (pg·h/mL) | 8 165 681 | 8 125 513 | 103.2 | 91.7–116.1 |
| (5 261 409) | (6 005 813) | |||
| Cmax (pg/mL) | 190 076 | 194 909 | 97.7 | 86.7–110.2 |
| (113 710) | (129 021) | |||
| AUCinf c (pg·h/mL) | 8 108 814 | 8 410 220 | 100.8 | 88.3–115.0 |
| (5 443 322) | (6 067 565) | |||
| Tmax (h) | 25.82 | 24.18 | 105.2 | 95.9–114.5 |
| (8.00) | (9.20) | |||
| Thalf (h)c | 58.03 | 55.09 | 103.2 | 96.1–110.3 |
| (22.46) | (16.41) | |||
| Vd (mL)c | 105 461 | 97 139 | 101.6 | 89.0–116.0 |
| (103 629) | (93 230) | |||
| Cl (mL/h) | 1185 | 1206 | 96.9 | 86.1–109.0 |
| (1072) | (858) |
The drug content of the batches of the proposed pegfilgrastim biosimilar and reference product employed in this study differed by greater than 5% (ie, 8%); any differences in PK parameter between the 2 products could be significantly obscured by this difference in drug content. To avoid bias by ensuring that the concentration data for pegfilgrastim were accurately reflective of the drug content of the test and reference products, prior to conducting PK and statistical analyses, the pegfilgrastim concentration data for the proposed biosimilar and reference product were corrected for protein content and purity of the corresponding batch used.
Based on the least‐squares estimates of the geometric means of AUCt, AUCinf, Cmax, Cl, and Vd and on arithmetic means for Tmax and Thalf parameters.
N = 50 for proposed pegfilgrastim biosimilar and n = 53 for reference product; Thalf, AUCinf, and Vd parameters were not determined if the log‐linear terminal phase was not clearly defined.