title: Pharmacokinetic analysis of melphalan after superselective ophthalmic artery infusion in preclinical models and retinoblastoma patients.
abstract: OBJECTIVE
  To characterize melphalan pharmacokinetics after superselective ophthalmic artery infusion (SSOAI) in animals and children with retinoblastoma.
  
  
  METHODS
  Vitreous and plasma samples of five Landrace pigs were obtained over a 4-hour period after SSOAI of melphalan (7 mg). Melphalan cytotoxicity was evaluated in retinoblastoma cell lines with and without topotecan. Plasma samples were obtained from 17 retinoblastoma patients after SSOAI of 3 to 6 mg of melphalan to one (n=14) or two eyes (n=3). Correlation between plasma pharmacokinetics and age, dosage, and systemic toxicity was studied in patients.
  
  
  RESULTS
  In animals, melphalan peak vitreous levels were greater than its IC50 and resulted in 3-fold vitreous-to-plasma exposure. In patients, a large variability in pharmacokinetic parameters was observed and it was explained mainly by body weight (P<0.05). A significantly higher systemic area under the curve was obtained in children receiving more than 0.48 mg/kg for bilateral tandem infusions (P<0.05). These children had 50% probability of grades 3-4 neutropenia. Plasma concentrations after 2 and 4 hours of SSOAI were significantly higher in these children (P<0.05). A synergistic cytotoxic effect of melphalan and topotecan was evident in cell lines.
  
  
  CONCLUSIONS
  Potentially active levels of melphalan after SSOAI were achieved in the vitreous of animals. Low systemic exposure was found in animals and children. Doses greater than 0.48 mg/kg, given for bilateral tandem infusions, were associated with significantly higher plasma levels and increased risk of neutropenia. Synergistic in vitro cytotoxicity between melphalan and topotecan favors combination treatment.
authors.affiliation: CONICET, Clinical Pharmacokinetics Unit, Hospital de Pediatría JP Garrahan, and Department of Pharmacology, Faculty of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina.
authors.forename: Paula
authors.initials: P
authors.lastname: Schaiquevich
authors.forename: Emiliano
authors.initials: E
authors.lastname: Buitrago
authors.forename: Paula
authors.initials: P
authors.lastname: Taich
authors.forename: Ana
authors.initials: A
authors.lastname: Torbidoni
authors.forename: Alejandro
authors.initials: A
authors.lastname: Ceciliano
authors.forename: Adriana
authors.initials: A
authors.lastname: Fandino
authors.forename: Marcelo
authors.initials: M
authors.lastname: Asprea
authors.forename: Flavio
authors.initials: F
authors.lastname: Requejo
authors.forename: David H
authors.initials: DH
authors.lastname: Abramson
authors.forename: Guillermo F
authors.initials: GF
authors.lastname: Bramuglia
authors.forename: Guillermo L
authors.initials: GL
authors.lastname: Chantada
mesh_terms: D000818:Animals; D018906:Antineoplastic Agents, Alkylating / Q000008:administration & dosage / Q000493:pharmacokinetics; D045744:Cell Line, Tumor; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007261:Infusions, Intra-Arterial; D008297:Male; D008558:Melphalan / Q000008:administration & dosage / Q000493:pharmacokinetics*; D009374:Neoplasms, Experimental; D009880:Ophthalmic Artery; D019572:Retinal Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D012175:Retinoblastoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D013552:Swine; D014822:Vitreous Body / Q000378:metabolism / Q000473:pathology
chemical_list: D018906:Antineoplastic Agents, Alkylating; D008558:Melphalan