title: Comparative preclinical and clinical pharmacokinetics of a cremophor-free, nanoparticle albumin-bound paclitaxel (ABI-007) and paclitaxel formulated in Cremophor (Taxol).
abstract: OBJECTIVE
  To compare the preclinical and clinical pharmacokinetic properties of paclitaxel formulated as a Cremophor-free, albumin-bound nanoparticle (ABI-007) and formulated in Cremophor-ethanol (Taxol).
  
  
  METHODS
  ABI-007 and Taxol were given i.v. to Harlan Sprague-Dawley male rats to determine pharmacokinetic and drug disposition. Paclitaxel pharmacokinetic properties also were assessed in 27 patients with advanced solid tumors who were randomly assigned to treatment with ABI-007 (260 mg/m(2), 30 minutes; n = 14) or Taxol (175 mg/m(2), 3 hours; n = 13), with cycles repeated every 3 weeks.
  
  
  RESULTS
  The volume of distribution at steady state and clearance for paclitaxel formulated as Cremophor-free nanoparticle ABI-007 were significantly greater than those for paclitaxel formulated with Cremophor (Taxol) in rats. Fecal excretion was the main elimination pathway with both formulations. Consistent with the preclinical data, paclitaxel clearance and volume of distribution were significantly higher for ABI-007 than for Taxol in humans [21.13 versus 14.76 L/h/m(2) (P = 0.048) and 663.8 versus 433.4 L/m(2) (P = 0.040), respectively].
  
  
  CONCLUSIONS
  Paclitaxel formulated as ABI-007 differs from paclitaxel formulated as Taxol, with a higher plasma clearance and a larger volume of distribution. This finding is consistent with the absence of paclitaxel-sequestering Cremophor micelles after administration of ABI-007. This unique property of ABI-007 could be important for its therapeutic effectiveness.
authors.affiliation: National Cancer Institute, Bethesda, Maryland 20892, USA. sparreba@mail.nih.gov
authors.forename: Alex
authors.initials: A
authors.lastname: Sparreboom
authors.forename: Charity D
authors.initials: CD
authors.lastname: Scripture
authors.forename: Vuong
authors.initials: V
authors.lastname: Trieu
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Williams
authors.forename: Tapas
authors.initials: T
authors.lastname: De
authors.forename: Andrew
authors.initials: A
authors.lastname: Yang
authors.forename: Bridget
authors.initials: B
authors.lastname: Beals
authors.forename: William D
authors.initials: WD
authors.lastname: Figg
authors.forename: Michael
authors.initials: M
authors.lastname: Hawkins
authors.forename: Neil
authors.initials: N
authors.lastname: Desai
mesh_terms: D000328:Adult; D000368:Aged; D000068196:Albumin-Bound Paclitaxel; D000418:Albumins / Q000008:administration & dosage / Q000493:pharmacokinetics; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000493:pharmacokinetics*; D019540:Area Under Curve; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D017239:Paclitaxel / Q000008:administration & dosage / Q000493:pharmacokinetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution
chemical_list: D000068196:Albumin-Bound Paclitaxel; D000418:Albumins; D000972:Antineoplastic Agents, Phytogenic; D017239:Paclitaxel