title: Pharmacokinetics, tissue distribution and excretion of 40kDa PEG and PEGylated rFVIII (N8-GP) in rats.
abstract: The biologic fate of the [(3)H]PEG-moiety incorporated into N8-GP was evaluated based on single i.v. bolus doses to rats. Furthermore, the 40kDa [(3)H]PEG-moiety was given separately to rats by single i.v. bolus doses, to investigate if the pharmacokinetics were dose-dependent. For both compounds, plasma pharmacokinetics, distribution and excretion pathways were investigated, based on total radioactivity measurements ([(3)H]N8-GP: 0.17-4.1mg/kg;~1300-30,000U/kg, PEG load of ~0.03-0.7mg/kg); ([(3)H]PEG: 0.6, 1, 12, 100 and 200mg/kg). The plasma concentration of the intact N8-GP conjugate was also measured by ELISA. After single i.v. administration to rats, both [(3)H]N8-GP and [(3)H]PEG were shown to be widely distributed, mainly in highly vascularized tissues, with the lowest levels of radioactivity found in the CNS. Though a slow elimination of radioactivity was observed over the 12-week study period, approximately half of the radioactive dose of either compound was removed from the body 1week post-dose. The radioactivity was eliminated mainly via the kidney into urine but also via the liver into feces, with a larger fraction found in the feces for [(3)H]N8-GP. Elimination of the 40kDa PEG-moiety was shown to be dose-dependent with faster elimination at lower dose levels. The clinical dose of N8-GP provides a substantially lower PEG exposure (50-75U/kg; PEG load of <0.002mg/kg) when compared to the PEG doses investigated in this paper (0.03-200mg/kg). This may imply an even faster clearance of the PEG-moiety after N8-GP administration of clinically relevant doses.
authors.affiliation: Development DMPK and Isotope Chemistry, Novo Nordisk A/S, Novo Nordisk Park, Måløv, Denmark. Electronic address: Inbj@novonordisk.com.
authors.forename: Inga
authors.initials: I
authors.lastname: Bjørnsdottir
authors.affiliation: Development DMPK and Isotope Chemistry, Novo Nordisk A/S, Novo Nordisk Park, Måløv, Denmark.
authors.forename: Ola
authors.initials: O
authors.lastname: Sternebring
authors.affiliation: Development DMPK and Isotope Chemistry, Novo Nordisk A/S, Novo Nordisk Park, Måløv, Denmark.
authors.forename: Wendela A
authors.initials: WA
authors.lastname: Kappers
authors.affiliation: Development DMPK and Isotope Chemistry, Novo Nordisk A/S, Novo Nordisk Park, Måløv, Denmark.
authors.forename: Helle
authors.initials: H
authors.lastname: Selvig
authors.affiliation: Development DMPK and Isotope Chemistry, Novo Nordisk A/S, Novo Nordisk Park, Måløv, Denmark.
authors.forename: Hanne T
authors.initials: HT
authors.lastname: Kornø
authors.affiliation: Development DMPK and Isotope Chemistry, Novo Nordisk A/S, Novo Nordisk Park, Måløv, Denmark.
authors.forename: Jesper B
authors.initials: JB
authors.lastname: Kristensen
authors.affiliation: Development DMPK and Isotope Chemistry, Novo Nordisk A/S, Novo Nordisk Park, Måløv, Denmark.
authors.forename: Morten A
authors.initials: MA
authors.lastname: Bagger
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D005169:Factor VIII / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006207:Half-Life; D008297:Male; D011092:Polyethylene Glycols / Q000008:administration & dosage / Q000493:pharmacokinetics*; D011849:Radioactive Tracers; D051381:Rats; D014018:Tissue Distribution
chemical_list: C579325:N8-GP compound; D011849:Radioactive Tracers; D011092:Polyethylene Glycols; D005169:Factor VIII
keywords: Distribution; Excretion; N8-GP; PEGylated rFVIII; Pharmacokinetics