title: Pharmacokinetic analysis of pegylated megakaryocyte growth and development factor in humans.
abstract: Phase I studies with pegylated megakaryocyte growth and development factor (PEG-rHuMGDF), a c-Mpl ligand that stimulates megakaryopoiesis, have demonstrated that PEG-rHuMGDF is biologically active alone and causes a dose-related enhancement of platelet recovery when administered after chemotherapy. Here we report the dose-ranging pharmacokinetics of PEG-rHuMGDF. Pre-injection blood samples were drawn daily for pharmacokinetic studies on 43 patients. An ELISA, established using PEG-rHuMGDF as the standard, was able to quantitate Mpl ligand at concentrations > 0.02 ng/mL. Over the dose range 0.03 to 5.0 microg/kg/day, subcutaneous administration produced linear increases in steady-state serum levels. Maximum levels of PEG-rHuMGDF attained after 5.0 microg/kg/day were 5.88 to 10.9 ng/mL. After discontinuation of PEG-rHuMGDF, concentrations of Mpl ligand returned to baseline within 5 days. The pharmacokinetics were best described by a one-compartment model with first-order absorption, an absorption delay, and non linear clearance over the first 48 hours. The mean terminal half-life was 33.3 + 16.7 hours, and the average apparent at steady state was 27.7 + 14.0 mL/h/kg; both were independent of administered dose. The apparent clearance of PEG-rHuMGDF was not predicted by platelet count. Administration of chemotherapy and Filgrastim did not alter the pharmacokinetics of PEG-rHuMGDF.
authors.affiliation: Ludwig Institute Oncology Unit, Austin Repatriation Medical Centre, Australia.
authors.forename: R H
authors.initials: RH
authors.lastname: De Boer
authors.forename: L K
authors.initials: LK
authors.lastname: Roskos
authors.forename: E
authors.initials: E
authors.lastname: Cheung
authors.forename: S
authors.initials: S
authors.lastname: Fox
authors.forename: R L
authors.initials: RL
authors.lastname: Basser
authors.forename: J
authors.initials: J
authors.lastname: Marty
authors.forename: C G
authors.initials: CG
authors.lastname: Begley
authors.forename: J
authors.initials: J
authors.lastname: Cebon
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D007279:Injections, Subcutaneous; D009369:Neoplasms / Q000097:blood / Q000188:drug therapy; D010976:Platelet Count; D011092:Polyethylene Glycols / Q000008:administration & dosage / Q000493:pharmacokinetics*; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D013926:Thrombopoietin / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D000970:Antineoplastic Agents; D011994:Recombinant Proteins; C103117:polyethylene glycol-recombinant human megakaryocyte growth and development factor; D011092:Polyethylene Glycols; D013926:Thrombopoietin