Pharmacokinetics of radiolabeled monoclonal antibody B6.2 in patients with metastatic breast cancer.

Journal Article (Journal Article)

Thirteen patients with metastatic breast carcinoma were given injections of 50-1593 micrograms of 131I-monoclonal antibody (MAb) B6.2 immunoglobulin G and F(ab')2 for pharmacokinetic evaluation and radioimmunoimaging. Blood clearance of the 131I-MAb-B6.2 was biphasic. The mean half-times (t 1/2 alpha, t 1/2 beta) for the immunoglobulin G were 3.5 +/- 1.7 and 20.9 +/- 11.0 h, respectively. The t 1/2 alpha for the F(ab')2 was 1.7 +/- 1.3 h, and the t 1/2 beta was 31.0 +/- 5.7 h. The percentage of protein bound 131I for the immunoglobulin G and for the F(ab')2 at 72 h was 73.7 +/- 11.4% and 58.2 +/- 14.5%, respectively. In vitro reactivity of MAb B6.2 with granulocytes isolated from normal subjects and patients was demonstrated by cytofluorometric and radioimmunoassays. MAb B6.2 was shown to bind with normal cross-reacting antigen, a cell surface antigen known to be expressed on normal human granulocytes. Reactivity with normal cross-reacting antigen on granulocytes is consistent with the skeletal images obtained during immunoscintigraphy of all 13 patients. A specific tumor image was observed in one patient. No toxicity was encountered. In spite of extensive preclinical data suggesting that 131I-MAb B6.2 would be a useful agent for radioimmunoimaging, the clinical utility of this reagent is probably limited because of the reactivity with granulocytes.

Full Text

Duke Authors

Cited Authors

  • Hayes, DF; Zalutsky, MR; Kaplan, W; Noska, M; Thor, A; Colcher, D; Kufe, DW

Published Date

  • June 1986

Published In

Volume / Issue

  • 46 / 6

Start / End Page

  • 3157 - 3163

PubMed ID

  • 3698030

Pubmed Central ID

  • 3698030

International Standard Serial Number (ISSN)

  • 0008-5472


  • eng

Conference Location

  • United States