The use of daunomycin-antibody immunoconjugates in managing soft tissue sarcomas: nude mouse xenograft model.

Abstract

Analysis of human fibrosarcoma cells exposed to radiolabeled monoclonal antibody 19-24, which recognizes sarcoma-associated antigen p102, revealed that over 54% of the cell surface-bound radioactivity was internalized. No modulation of cell surface p102 antigen by monoclonal antibody 19-24 was observed in human fibrosarcoma cells. Monoclonal antibody 19-24 coupled to daunomycin via a dextran bridge was found to be most effective. In different preparations, the daunomycin:total protein molar ratio ranged from 1.9 to 6.1. In vitro cytotoxicity studies using human fibrosarcoma cells showed that, at 10 micrograms/ml concentration, this immunoconjugate was 79.4% as efficient as free daunomycin and, at 1 microgram/ml concentration, 36.8% as efficient. Control nonspecific murine monoclonal antibody P3 immunoconjugates were relatively ineffective. The distribution of 14C-Adriamycin, 125I-labeled monoclonal antibody 19-24, and 125I-labeled 19-24 immunoconjugate was also evaluated over a 24-h period in tumor and normal tissues of athymic mice bearing a human fibrosarcoma xenograft. Poor uptake of radiolabeled Adriamycin by the tumor tissue was observed. The level of 14C radioactivity in the tumor tissue never exceeded 1% of the total injected dose and was 24.8-fold lower than the radioactivity found in the spleen tissue. Tumor tissue uptake of radiolabeled monoclonal antibody 19-24 was characterized by the high tumor tissue:blood ratio of 1.62 +/- 0.28 (SD). However, for monoclonal antibody 19-24 immunoconjugates, this ratio decreased to 0.66 +/- 0.05, which was still higher than normal (liver, 0.48 +/- 0.02; lung, 0.48 +/- 0.07; spleen, 0.28 +/- 0.01) or nonspecific monoclonal antibody P3 immunoconjugates (0.22 +/- 0.03). Thus, it appears that, compared to free daunomycin, monoclonal antibody 19-24 immunoconjugates may be more efficient and less cytotoxic to normal tissues.

• Authors: J J Stastny, T K Das Gupta
• Journal: Cancer research (Cancer Res) Vol. 53 Issue 23 Pg. 5740-4 (Dec 01 1993) ISSN: 0008-5472 [Print] United States
• PMID: 8242630 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Antibodies, Monoclonal
• Immunotoxins
• Doxorubicin
• Daunorubicin

Topics

• Animals
• Antibodies, Monoclonal (metabolism, therapeutic use)
• Daunorubicin (pharmacokinetics, therapeutic use)
• Doxorubicin (pharmacokinetics)
• Humans
• Immunotoxins (metabolism, therapeutic use)
• Male
• Mice
• Mice, Nude
• Neoplasm Transplantation
• Sarcoma, Experimental (therapy)
• Soft Tissue Neoplasms (therapy)
• Tissue Distribution
• Transplantation, Heterologous