Pharmacokinetic model of iodine-131-G250 antibody in renal cell carcinoma patients Journal Article


Authors: Loh, A.; Sgouros, G.; O'Donoghue, J. A.; Deland, D.; Puri, D.; Capitelli, P.; Humm, J. L.; Larson, S. M.; Old, L. J.; Divgi, C. R.
Article Title: Pharmacokinetic model of iodine-131-G250 antibody in renal cell carcinoma patients
Abstract: A model that describes the pharmacokinetic distribution of 131I- labeled G250 antibody is developed. Methods: Previously collected pharmacokinetic data from a Phase HI study of 131I-G250 murine antibody against renal cell carcinoma were used to develop a mathematical model describing antibody clearance from serum and the whole body. Survey meter measurements, obtained while the patient was under radiation precautions, and imaging data, obtained at later times, were combined to evaluate whole-body clearance kinetics over an extended period. Results: A linear two-compartment model was found to provide good fits to the data. The antibody was injected into Compartment 1, the initial distribution volume (V(d)) of the antibody, which included serum. The antibody exchange with the rest of the body, Compartment 2, and was eventually excreted. Data from 13 of the 16 patients fit the model with unique parameters; the maximum, median and minimum values for model-derived V(d) were 6.3, 3.7 and 2.11, respectively. The maximum, median and minimum values for the excretion rate were 8 x 10-2, 2.4 x 10- 2 and 1.3 x 10-2 hr-1, respectively. Parameter sensitivity analysis showed that a change in the transfer rate constant from serum to the rest of the body had the greatest effect on serum cumulative activity and that the rate constant for excretion had the greatest effect on whole-body cumulative activity. Conclusion: A linear two-compartment model was adequate in describing the serum and whole-body kinetics of G250 antibody distribution. The median initial distribution volume predicted by the model was consistent with the nominal value of 3.81. A wide variability in fitted parameters was observed among patients, reflecting the differences in individual patient clearance and exchange kinetics of G250 antibody. By selecting median parameter values, such a model may be used to evaluate and design prolonged multiple administration radioimmunotherapy protocols.
Keywords: adult; clinical article; aged; middle aged; clinical trial; area under the curve; treatment planning; antineoplastic agents; phase 2 clinical trial; kidney carcinoma; kidney neoplasms; mathematical model; models, theoretical; antibodies, monoclonal; iodine 131; drug distribution; tissue distribution; carcinoma, renal cell; iodine radioisotopes; phase 1 clinical trial; radioimmunotherapy; antibody; pharmacokinetics; compartment model; modeling; clearance; humans; human; male; female; priority journal; article
Journal Title: Journal of Nuclear Medicine
Volume: 39
Issue: 3
ISSN: 0161-5505
Publisher: Society of Nuclear Medicine  
Date Published: 1998-03-01
Start Page: 484
End Page: 489
Language: English
PUBMED: 9529296
PROVIDER: scopus
DOI/URL:
Notes: Article -- Export Date: 12 December 2016 -- Source: Scopus
Citation Impact
MSK Authors
  1. George Sgouros
    146 Sgouros
  2. Chaitanya Divgi
    163 Divgi
  3. John Laurence Humm
    433 Humm
  4. Steven M Larson
    958 Larson
  5. Lloyd J Old
    593 Old