Recombinant Anti-Human EGFR VHH Single Domain Antibody (7D12)

Figure 1 In vitro characterisation of selected monovalent anti‐EGFR sdAbs.

The binding of biotinylated EGF (800 pM) to an EGFR‐ECD‐Fc fusion was tested in the presence of increasing amounts of the 9G8, 7D12, 7C12 or 38G7 sdAbs, or without sdAb. Receptor‐bound EGF was then detected via peroxidase‐coupled streptavidin and staining with OPD/H2O2.

Roovers, R. C., Vosjan, M. J., Laeremans, T., el Khoulati, R., de Bruin, R. C., Ferguson, K. M., ... & van Bergen en Henegouwen, P. M. (2011). A biparatopic anti‐EGFR sdAb efficiently inhibits solid tumour growth. International journal of cancer, 129(8), 2013-2024.

Figure 2 In vitro characterisation of selected monovalent anti‐EGFR sdAbs.

The binding of 7D12 sdAbs to EGFR, expressed on phage, was detected in a 100-fold molar excess of the indicated antibody (cetuximab) or antibody fragments.

Roovers, R. C., Vosjan, M. J., Laeremans, T., el Khoulati, R., de Bruin, R. C., Ferguson, K. M., ... & van Bergen en Henegouwen, P. M. (2011). A biparatopic anti‐EGFR sdAb efficiently inhibits solid tumour growth. International journal of cancer, 129(8), 2013-2024.

Figure 3 Inhibition of A431 tumour cell proliferation by monovalent and bivalent sdAbs.

The proliferation of A431 cells in the presence of increasing amounts of sdAb monovalent and bivalent 7D12; was measured using a sulphorhodaminebased stain of total cellular protein after TCA precipitation. Proliferation is plotted as percentage of maximal growth (cells left without treatment). The whole antibody cetuximab was used as ''standard'' in every test. Data points where the value of the control is statistically different from that of the sdAb-treated group are indicated by an asterisk.

Roovers, R. C., Vosjan, M. J., Laeremans, T., el Khoulati, R., de Bruin, R. C., Ferguson, K. M., ... & van Bergen en Henegouwen, P. M. (2011). A biparatopic anti‐EGFR sdAb efficiently inhibits solid tumour growth. International journal of cancer, 129(8), 2013-2024.

Figure 4 Inhibition of A431 tumour cell proliferation by monovalent and bivalent sdAbs.

The proliferation of A431 cells in the presence of increasing amounts of sdAb mixtures of monovalent and bivalent 7D12 and 9G8; was measured using a sulphorhodaminebased stain of total cellular protein after TCA precipitation. Proliferation is plotted as percentage of maximal growth (cells left without treatment). The whole antibody cetuximab was used as ''standard'' in every test. Data points where the value of the control is statistically different from that of the sdAb-treated group are indicated by an asterisk; only different between 7D12þ9G8 and control.

Roovers, R. C., Vosjan, M. J., Laeremans, T., el Khoulati, R., de Bruin, R. C., Ferguson, K. M., ... & van Bergen en Henegouwen, P. M. (2011). A biparatopic anti‐EGFR sdAb efficiently inhibits solid tumour growth. International journal of cancer, 129(8), 2013-2024.

Figure 6 In vitro optimalisation and characterisation of trivalent biparatopic sdAb CONAN-1.

The proliferation of A431 cells in the presence of increasing amounts of biparatopic sdAb 7D12-9G8 (with linkers varying in length between the two sdAb units) was measured using a sulphorhodamine-based stain of total cellular protein after TCA precipitation. Proliferation is plotted as percentage of maximal growth (cells left without treatment). Error bars have been omitted to increase the clarity of the figure. The different linker lengths between the two sdAbs are indicated.

Roovers, R. C., Vosjan, M. J., Laeremans, T., el Khoulati, R., de Bruin, R. C., Ferguson, K. M., ... & van Bergen en Henegouwen, P. M. (2011). A biparatopic anti‐EGFR sdAb efficiently inhibits solid tumour growth. International journal of cancer, 129(8), 2013-2024.

Figure 7 In vitro optimalisation and characterisation of trivalent biparatopic sdAb CONAN-1.

Purified EGFR-ECD-Fc fusion protein was immobilised via a coated anti-human Fc anti-serum, and a concentration range of either bivalent (7D12-9G8) or trivalent (CONAN-1) sdAb was bound. The binding of biotinylated mouse serum albumin (MSA) was subsequently detected with peroxidase-conjugated streptavidin and staining with OPD/H2O2.

Roovers, R. C., Vosjan, M. J., Laeremans, T., el Khoulati, R., de Bruin, R. C., Ferguson, K. M., ... & van Bergen en Henegouwen, P. M. (2011). A biparatopic anti‐EGFR sdAb efficiently inhibits solid tumour growth. International journal of cancer, 129(8), 2013-2024.

Figure 8 In vitro optimalisation and characterisation of trivalent biparatopic sdAb CONAN-1.

The proliferation of A431 cells in the presence of increasing amounts of sdAb was measured using the sulphorhodamine B assay. The effect of the presence of human serum albumin (HSA: 1%) in the medium was assessed.

Roovers, R. C., Vosjan, M. J., Laeremans, T., el Khoulati, R., de Bruin, R. C., Ferguson, K. M., ... & van Bergen en Henegouwen, P. M. (2011). A biparatopic anti‐EGFR sdAb efficiently inhibits solid tumour growth. International journal of cancer, 129(8), 2013-2024.

Figure 9 In vitro specificity of ⁹⁹ᵐTc-7C12 and ⁹⁹ᵐTc-7D12 on A431 cell line after 2-h incubation on ice.

Binding of labeled compound was blocked by 1,000-fold excess of unlabeled 99mTc-7C12, ⁹⁹ᵐTc-7D12, or cetuximab.

Gainkam, L. O. T., Huang, L., Caveliers, V., Keyaerts, M., Hernot, S., Vaneycken, I., ... & Lahoutte, T. (2008). Comparison of the biodistribution and tumor targeting of two 99mTc-labeled anti-EGFR sdAbs in mice, using pinhole SPECT/micro-CT. Journal of Nuclear Medicine, 49(5), 788-795.

Figure 10 Tumor uptake (%IA/g) of ⁹⁹ᵐTc-7D12 expressed as function of tumor weight in nu/nu mouse A431 xenografts.

Animals were dissected at 1.5 h after injection of tracer. Tumor uptake, in %IA/g, decreased with increasing tumor size.

Gainkam, L. O. T., Huang, L., Caveliers, V., Keyaerts, M., Hernot, S., Vaneycken, I., ... & Lahoutte, T. (2008). Comparison of the biodistribution and tumor targeting of two 99mTc-labeled anti-EGFR sdAbs in mice, using pinhole SPECT/micro-CT. Journal of Nuclear Medicine, 49(5), 788-795.

Figure 11 Blood clearance.

Non–tumor-bearing nu/nu mice (n53) received intravenous injection of ⁹⁹ᵐTc-7C12 or 99mTc7D12. Blood samples were collected at indicated time points and analyzed with g-counter. Half-life was determined using biexponential nonlinear regression fit (GraphPad Prism).

Gainkam, L. O. T., Huang, L., Caveliers, V., Keyaerts, M., Hernot, S., Vaneycken, I., ... & Lahoutte, T. (2008). Comparison of the biodistribution and tumor targeting of two 99mTc-labeled anti-EGFR sdAbs in mice, using pinhole SPECT/micro-CT. Journal of Nuclear Medicine, 49(5), 788-795.

Figure 12 7D12 and 425scFv retain binding capacity to EGFR after coupling to liposomes and EGFR downregulation is a specific feature of sdAb-liposomes.

The binding of 7D12 to EGFR was tested in the presence of: EGa1 sdAb (EGa1), EGa1-liposomes (EGa1-L 0.4 and EGa1-L 0.8), 7D12 sdAb (7D12), 7D12- liposomes (7D12-L 0.4), 425 single chain variable fragment (425scFv), 425scFvliposomes (425scFv-L 0.4), Erbitux, and liposomes (L). Bound phage were detected with a HRP-coupled anti-M13 monoclonal antibody and staining with OPD/H2O.

Oliveira, S., Schiffelers, R. M., van der Veeken, J., van der Meel, R., Vongpromek, R., en Henegouwen, P. M. V. B., ... & Roovers, R. C. (2010). Downregulation of EGFR by a novel multivalent sdAb-liposome platform. Journal of Controlled Release, 145(2), 165-175.

Figure 13 7D12 and 425scFv retain binding capacity to EGFR after coupling to liposomes and EGFR downregulation is a specific feature of sdAb-liposomes.

The binding of EGa1-phage to EGFR was tested in the presence of: EGa1 sdAb (EGa1), EGa1-liposomes (EGa1-L 0.4 and EGa1-L 0.8), 7D12 sdAb (7D12), 7D12- liposomes (7D12-L 0.4), 425 single chain variable fragment (425scFv), 425scFvliposomes (425scFv-L 0.4), Erbitux, and liposomes (L). Bound phage were detected with a HRP-coupled anti-M13 monoclonal antibody and staining with OPD/H2O.

Oliveira, S., Schiffelers, R. M., van der Veeken, J., van der Meel, R., Vongpromek, R., en Henegouwen, P. M. V. B., ... & Roovers, R. C. (2010). Downregulation of EGFR by a novel multivalent sdAb-liposome platform. Journal of Controlled Release, 145(2), 165-175.

Figure 14 7D12 and 425scFv retain binding capacity to EGFR after coupling to liposomes and EGFR downregulation is a specific feature of sdAb-liposomes.

Cells were incubated for 4 h at 37 °C with different liposome formulations: EGa1-L, 7D12-L and 425scFv-L. After the incubation with liposomes at 0.5, 0.25 and 0.125 mM TL concentrations, cells were further incubated for 2 days. Thereafter, the level of cell surface EGFR was determined.

Oliveira, S., Schiffelers, R. M., van der Veeken, J., van der Meel, R., Vongpromek, R., en Henegouwen, P. M. V. B., ... & Roovers, R. C. (2010). Downregulation of EGFR by a novel multivalent sdAb-liposome platform. Journal of Controlled Release, 145(2), 165-175.