SPECT Imaging with 99mTc-Labeled EGFR-Specific Nanobody for In Vivo Monitoring of EGFR Expression

Huang, Lieven; Gainkam, Lea Olive Tchouate; Caveliers, Vicky; Vanhove, Christian; Keyaerts, Marleen; Baetseĺier, Patrick De; Bossuyt, A.; Revets, Hilde; Lahoutte, Tony

doi:10.1007/s11307-008-0133-8

Cited by 159 publications

(141 citation statements)

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“…Although hepatic accumulation of both Nanobodies was observed, uptake was very low compared with studies using 99m Tc-Nanobodies (18,19), 64 Cu-labeled cetuximab, and 99m Tc-labeled affibody (20,21). 99m Tc-7D12 uptake was higher in the liver and lower in the kidneys than was 99m Tc-7C12 uptake.…”

Section: Discussionmentioning

confidence: 61%

Comparison of the Biodistribution and Tumor Targeting of Two ^99mTc-Labeled Anti-EGFR Nanobodies in Mice, Using Pinhole SPECT/Micro-CT

Gainkam¹,

et al. 2008

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Camelidae possess an unusual class of antibodies devoid of light chains. Nanobodies are intact antigen-binding fragments that are stable, easily generated against different targets, and fully functional. Their rapid clearance from the blood circulation favors their use as imaging agents. We compared the in vivo tumor uptake and biodistribution of 2 anti-epidermal growth factor receptor (anti-EGFR) Nanobodies, 99m Tc-7C12 and 99m Tc-7D12. Methods: Nanobodies were labeled via their hexahistidine tail with 99m Tc-tricarbonyl ( 99m Tc(CO) 3 ) generated from a kit. Mice bearing subcutaneous A431 (EGFR-positive) and R1M (EGFRnegative) xenografts were intravenously injected with 99m Tc-7C12 and 99m Tc-7D12 on separate days. Pinhole SPECT/ micro-CT images were acquired at 1 h after administration to assess noninvasively the biodistribution and tumor targeting of the labeled compounds. Pinhole SPECT and micro-CT images from the same mouse were automatically fused on the basis of a mathematic rigid-body-transformation algorithm using six 57 Co sources. Images were quantified, and tracer uptake was expressed as percentage injected activity per gram per cubic centimeter (%IA/cm 3 ) of tissue. Ex vivo biodistribution of mice bearing A431 injected with either 99m Tc-7C12 or 99m Tc-7D12 was also assessed; activity in the tumor and organs was recorded and expressed as percentage injected activity per gram (%IA/g). Results: Binding of both tracers was receptorspecific. Image analysis showed high and similar tumor uptake values for both 99m Tc-7C12 and 99m Tc-7D12 (4.55 6 0.24 %IA/ cm 3 and 4.62 6 0.36 %IA/cm 3 , respectively) in A431 xenografts, whereas the uptake in the negative tumor (R1M) was low (1.16 6 0.14 for 99m Tc-7C12 and 1.49 6 0.60 for 99m Tc-7D12). 99m Tc-7C12 showed significantly higher kidney uptake (63.48 6 2.36 vs. 56.25 6 2.46 %IA/cm 3 ) and lower liver uptake (2.55 6 0.26 vs. 4.88 6 0.86 %IA/cm 3 ) than did 99m Tc-7D12. The ex vivo analysis confirmed the image quantification with high tumor-tobackground ratio; however, 99m Tc-7C12 showed higher tumor uptake (9.11 6 1.12 %IA/g) than did 99m Tc-7D12 (6.09 6 0.77 %IA/g). 99m Tc-7D12 demonstrated significantly higher blood activity than did 99m Tc-7C12, but both showed short plasma half-lives (,10 min).Conclusion: The Nanobody fragments used here show high tumor uptake, low liver uptake, and rapid blood clearance. Nanobodies are promising probes for noninvasive radioimmunodetection of specific targets early after administration. On the basis of its favorable biodistribution, 99m Tc-7C12 was selected for further studies. Epi dermal growth factor receptor (EGFR or ErbB1) is a member of a receptor tyrosine kinase family together with Her-2-neu/ErbB2, HER-3/ErbB3, and HER-4/ErbB4. EGFR is implicated in many cellular processes such as proliferation, differentiation, and survival (1). Several reports have shown that EGFR signaling is abnormal in many tumors of epithelial origin, such as cancer of the breast, head and neck, prostate, lung, and skin. Aberrant signaling of...

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Section: Discussionmentioning

confidence: 61%

Comparison of the Biodistribution and Tumor Targeting of Two ^99mTc-Labeled Anti-EGFR Nanobodies in Mice, Using Pinhole SPECT/Micro-CT

Gainkam¹,

et al. 2008

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“…With the recent identification of a universal humanized nanobody scaffold, these probes are now also ready for clinical translation (8,9). In our previous work we identified 99m Tc-7C12 nanobody (Ablynx NV) as the lead compound for monitoring EGFR expression of cancer based on its high tumor uptake, fast blood clearance and low liver uptake (10,11). High-contrast images of EGFR-expressing lesions can be obtained as early as 1 h post injection (p.i.).…”

Section: Full Papermentioning

confidence: 99%

Localization, mechanism and reduction of renal retention of technetium‐99m labeled epidermal growth factor receptor‐specific nanobody in mice

Gainkam

Caveliers

Devoogdt

et al. 2010

Contrast Media & Molecular

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Background: Nanobodies are single-domain antigen binding fragments derived from functional heavy-chain antibodies elicited in Camelidae. They are powerful probes for radioimmunoimaging, but their renal uptake is relatively high. In this study we have evaluated the role of megalin on the renal uptake of anti-EGFR 99m Tc-7C12 nanobody and the potency of gelofusine and/or lysine to reduce renal uptake of 99m Tc-7C12. Methods: First we compared the renal uptake of 99m Tc-7C12 in megalin-deficient and megalin-wild-type mice using pinhole SPECT/microCT and ex vivo analysis. The effect of gelofusine and lysine administration on renal accumulation of 99m Tc-7C12 was analyzed in CD-1 mice divided into lysine preload at 30 min before tracer injection (LysPreload), LysPreload R gelofusine coadministration (LysPreload R GeloCoad), lysine coadministration (LysCoad), gelofusine coadministration (GeloCoad) and LysCoad R GeloCoad. The combined effect of gelofusine and lysine on tumor uptake was tested in mice xenografts. Results: Renal uptake of 99m Tc-7C12 was 44.22 W 3.46% lower in megalin-deficient compared with megalinwild-type mice. In CD-1 mice, lysine preload had no effect on the renal retention whereas coinjection of lysine or gelofusine with the tracer resulted in 25.12 W 2.99 and 36.22 W 3.07% reduction, respectively. The combined effect of gelofusine and lysine was the most effective, namely a reduction of renal retention of 45.24 W 2.09%. Gelofusine and lysine coadministration improved tumor uptake. Conclusion: Megalin contributes to the renal accumulation of 99m Tc-7C12. Gelofusine and lysine coinjection with the tracer reduces the renal uptake while tumor uptake is improved. Although this methodology allows for optimization of imaging protocol using nanobodies, further improvements are needed before using these molecules for radionuclide therapy.

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“…Initial biodistribution studies with monospecific anti-EGFR (aEGFR)-Nanobodies in tumor-bearing mice showed, as expected, rapid blood clearance with a serum half-life time of less than an hour and low tumor uptake (15)(16)(17). Therefore, monospecific Nanobodies do not seem to be qualified for long-term blockage of growth factors and their receptors.…”

Section: Introductionmentioning

confidence: 89%

Nanobodies Targeting the Hepatocyte Growth Factor: Potential New Drugs for Molecular Cancer Therapy

Vosjan

Vercammen

Kolkman

et al. 2012

Molecular Cancer Therapeutics

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Hepatocyte growth factor (HGF) and its receptor c-Met are associated with increased aggressiveness of tumors and poor prognostic outcome of patients with cancer. Here, we report the development and characterization of therapeutic anti-HGF (aHGF)-Nanobodies and their potential for positron emission tomographic (PET) imaging to assess HGF expression in vivo. Two aHGF-Nanobodies designated 1E2 and 6E10 were identified, characterized, and molecularly fused to an albumin-binding Nanobody unit (Alb8) to obtain serum half-life extension. The resulting Nanobody formats were radiolabeled with the positron emitter zirconium-89 ( 89 Zr, t1/ 2 ¼ 78 hours), administered to nude mice bearing U87 MG glioblastoma xenografts, and their biodistribution was assessed. In addition, their therapeutic effect was evaluated in the same animal model at doses of 10, 30, or 100 mg per mouse. The 89 Zr-Nanobodies showed similar biodistribution with selective tumor targeting. For example, 1E2-Alb8 showed decreased blood levels of 12.6%ID/g AE 0.6%ID/g, 7.2%ID/g AE 1.0%ID/g, 3.4%ID/g AE 0.3%ID/g, and 0.3%ID/g AE 0.1%ID/g at 1, 2, 3, and 7 days after injection, whereas tumor uptake levels remained relatively stable at these time points: 7.8%ID/g AE 1.1%ID/g, 8.9%ID/g AE 1.0%ID/g, 8.7%ID/g AE 1.5%ID/g, and 7.2%ID/g AE1.6%ID/g. Uptake in normal tissues was lower than in tumor, except for kidneys. In a therapy study, all Nanobody-treated mice showed tumor growth delay compared with the control saline group. In the 100-mg group, four of six mice were cured after treatment with 1E2-Alb8 and 73 days follow-up, and three of six mice when treated with 6E10-Alb8. These results provide evidence that Nanobodies 1E2-Alb8 and 6E10-Alb8 have potential for therapy and PET imaging of HGFexpressing tumors.

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SPECT Imaging with 99mTc-Labeled EGFR-Specific Nanobody for In Vivo Monitoring of EGFR Expression

Cited by 159 publications

References 60 publications

Comparison of the Biodistribution and Tumor Targeting of Two ^99mTc-Labeled Anti-EGFR Nanobodies in Mice, Using Pinhole SPECT/Micro-CT

Comparison of the Biodistribution and Tumor Targeting of Two ^99mTc-Labeled Anti-EGFR Nanobodies in Mice, Using Pinhole SPECT/Micro-CT

Localization, mechanism and reduction of renal retention of technetium‐99m labeled epidermal growth factor receptor‐specific nanobody in mice

Nanobodies Targeting the Hepatocyte Growth Factor: Potential New Drugs for Molecular Cancer Therapy

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SPECT Imaging with 99mTc-Labeled EGFR-Specific Nanobody for In Vivo Monitoring of EGFR Expression

Cited by 159 publications

References 60 publications

Comparison of the Biodistribution and Tumor Targeting of Two 99mTc-Labeled Anti-EGFR Nanobodies in Mice, Using Pinhole SPECT/Micro-CT

Comparison of the Biodistribution and Tumor Targeting of Two 99mTc-Labeled Anti-EGFR Nanobodies in Mice, Using Pinhole SPECT/Micro-CT

Localization, mechanism and reduction of renal retention of technetium‐99m labeled epidermal growth factor receptor‐specific nanobody in mice

Nanobodies Targeting the Hepatocyte Growth Factor: Potential New Drugs for Molecular Cancer Therapy

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Resources

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Comparison of the Biodistribution and Tumor Targeting of Two ^99mTc-Labeled Anti-EGFR Nanobodies in Mice, Using Pinhole SPECT/Micro-CT

Comparison of the Biodistribution and Tumor Targeting of Two ^99mTc-Labeled Anti-EGFR Nanobodies in Mice, Using Pinhole SPECT/Micro-CT