Selective targeting of tumour neovasculature by a radiohalogenated human antibody fragment specific for the ED-B domain of fibronectin

Abstract. Angiogenesis is a characteristic feature of many aggressive tumours and other disorders. Antibodies capable of binding to new blood vessels, but not to mature vessels, could be used as selective targeting agents for immunoscintigraphic and radioimmunotherapeutic applications. Here we show that scFv(L19), a recombinant human antibody fragment with sub-nanomolar affinity for the ED-B domain of fibronectin, a marker of angiogenesis, can be stably labelled with iodine-125 and astatine-211 with full retention of immunoreactivity, using a trimethyl-stannyl benzoate bifunctional derivative. Biodistribution studies in mice bearing two different types of tumour grafted subcutaneously, followed by ex vivo micro-autoradiographic analysis, revealed that scFv(L19) rapidly localises around tumour blood vessels, but not around normal vessels. Four hours after intravenous injection of the stably radioiodinated scFv(L19), tumour to blood ratios were 6:1 in mice bearing the F9 murine teratocarcinoma and 9:1 in mice bearing an FE8 rat sarcoma. As expected, all other organs (including kidney) contained significantly less radioactivity than the tumour. Since the ED-B domain of fibronectin has an identical sequence in mouse and man, scFv(L19) is a pan-species antibody and the results presented here suggest clinical utility of radiolabelled scFv(L19) for the scintigraphic detection of angiogenesis in vivo. Furthermore, it should now be possible to investigate scFv(L19) for the selective delivery of 211At to the tumour neovasculature, causing the selective death of tumour endothelial cells and tumour collapse.

[1]  L. Zardi,et al.  The fibronectin isoform containing the ed‐b oncofetal domain: A marker of angiogenesis , 1994, International journal of cancer.

[2]  C. Elbaz,et al.  [Vessels]. , 2018, Algerie medicale.

[3]  Dario Neri,et al.  Targeting by affinity–matured recombinant antibody fragments of an angiogenesis associated fibronectin isoform , 1997, Nature Biotechnology.

[4]  A. Pini,et al.  Phage antibodies with pan‐species recognition of the oncofoetal angiogenesis marker fibronectin ED‐B domain , 1996, International journal of cancer.

[5]  H. Kosmehl,et al.  Targeted delivery of tissue factor to the ED-B domain of fibronectin, a marker of angiogenesis, mediates the infarction of solid tumors in mice. , 2001, Cancer research.

[6]  A. Pini,et al.  Design and Use of a Phage Display Library , 1998, The Journal of Biological Chemistry.

[7]  K. Wüthrich,et al.  NMR structure of the human oncofoetal fibronectin ED-B domain, a specific marker for angiogenesis. , 1999, Structure.

[8]  S. Kennel,et al.  Vascular targeted radioimmunotherapy with 213Bi--an alpha-particle emitter. , 1998, Nuclear medicine and biology.

[9]  B. Ephrussi,et al.  Alkaline phosphatase activity in mouse teratoma. , 1973, Proceedings of the National Academy of Sciences of the United States of America.

[10]  F. Baralle,et al.  Transformed human cells produce a new fibronectin isoform by preferential alternative splicing of a previously unobserved exon. , 1987, The EMBO journal.

[11]  D. Bigner,et al.  Radioimmunotherapy with alpha-particle emitting radioimmunoconjugates. , 1996, Acta oncologica.

[12]  L. Dinkelborg,et al.  HEMOSTASIS, THROMBOSIS, AND VASCULAR BIOLOGY A High-Affinity Human Antibody That Targets Tumoral Blood Vessels , 1999 .

[13]  D. Bigner,et al.  Synthesis of radioiodinated N-succinimidyl iodobenzoate: optimization for use in antibody labelling. , 1989, International journal of radiation applications and instrumentation. Part A, Applied radiation and isotopes.

[14]  L. Zardi,et al.  Increased binding affinity and valence of recombinant antibody fragments lead to improved targeting of tumoral angiogenesis. , 1999, Cancer research.

[15]  S. Kennel,et al.  Vascular targeted radioimmunotherapy with 213Bi-An α-particle emitter , 1998 .

[16]  A. Nirkko,et al.  Partial reversion of the transformed phenotype in HRAS-transfected tumorigenic cells by transfer of a human gene. , 1988, Proceedings of the National Academy of Sciences of the United States of America.

[17]  Dario Neri,et al.  Selective targeting and photocoagulation of ocular angiogenesis mediated by a phage-derived human antibody fragment , 1999, Nature Biotechnology.

[18]  D. Bigner,et al.  Radioimmunotherapy with α-Particle Emitting Radioimmunoconjugates , 1996 .

[19]  J. Folkman.  Angiogenesis in cancer, vascular, rheumatoid and other disease , 1995, Nature Medicine.