Enhanced Tumor Retention of a Radiohalogen Label for Site-Specific Modification of Antibodies

Boswell, C. Andrew; Mařı́k, Jan; Elowson, Michael J.; Reyes, Noe A; Ulufatu, Sheila; Bumbaca, Daniela; Yip, Victor; Mundo, Eduardo E.; Majidy, Nicholas; Hoy, Marjie Van; Goriparthi, Saritha N; Trias, Anthony; Gill, Herman; Williams, Simon P.; Junutula, Jagath R.; Fielder, Paul J.; Khawli, Leslie A.

doi:10.1021/jm401365h

Cited by 38 publications

(32 citation statements)

References 34 publications

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“…5 A) at 48 h post administration revealed that FcRn binding impairment by point mutations yielded ~3-fold signal reduction in tumor and most tissues, largely mirroring exposure. Consistent with previous work, far less tumor uptake was observed with the non-residualizing 125 I label than with 111 In-DOTA (31). Distribution of 125 I-7C2-TCO 6 and 125 I-7C2-HAHQ-TCO 6 (hatched blue and black, respectively, Supplementary Fig.…”

Section: Pharmacokinetics and Biodistributionsupporting

confidence: 89%

Effect of Modulating FcRn Binding on Direct and Pretargeted Tumor Uptake of Full-length Antibodies

Nazarova¹,

Rafidi²,

Mandikian³

et al. 2020

Molecular Cancer Therapeutics

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Full-length antibodies lack ideal pharmacokinetic properties for rapid targeted imaging, prompting the pursuit of smaller peptides and fragments. Nevertheless, studying the disposition properties of antibody-based imaging agents can provide critical insight into the pharmacology of their therapeutic counterparts, particularly for those coupled with potent payloads. Here, we evaluate modulation of binding to the neonatal Fc receptor (FcRn) as a protein engineering-based pharmacological strategy to minimize the overall blood pool background with directly labeled antibodies and undesirable systemic click reaction of radiolabeled tetrazine with circulating pretargeted trans-cyclooctene (TCO)-modified antibodies. Noninvasive SPECT imaging of mice bearing HER2-expressing xenografts was performed both directly (111 In-labeled antibody) and indirectly (pretargeted TCO-modified antibody followed by 111 In-labeled tetrazine). Pharmacokinetic modulation of antibodies was achieved by two distinct methods: Fc engineering to reduce binding affinity to FcRn, and delayed administration of an antibody that competes with binding to FcRn. Tumor imaging with directly labeled antibodies was feasible in the absence of FcRn binding, rapidly attaining high tumor-to-blood ratios, but accompanied by moderate liver and spleen uptake. Pretargeted imaging of tumors with non-FcRn-binding antibody was also feasible, but systemic click reaction still occurred, albeit at lower levels than with parental antibody. Our findings demonstrate that FcRn binding impairment of full-length IgG antibodies moderately lowers tumor accumulation of radioactivity, and shifts background activity from blood pool to liver and spleen. Furthermore, reduction of FcRn binding did not eliminate systemic click reaction, but yielded greater improvements in tumor-to-blood ratio when imaging with directly labeled antibodies than with pretargeting.

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Section: Pharmacokinetics and Biodistributionsupporting

confidence: 89%

Effect of Modulating FcRn Binding on Direct and Pretargeted Tumor Uptake of Full-length Antibodies

Nazarova¹,

Rafidi²,

Mandikian³

et al. 2020

Molecular Cancer Therapeutics

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“…[295][296][297][298] Most of the optical thiol-selective fluorescent probes often used as sensors for monitoring biological processes are represented by maleimide-containing reagents. [299][300][301] Another testament to maleimide utility is its use in glycosylation, 302 radiolabelling, 303,304 studying protein interactions, [305][306][307][308] and quantitation of cysteine residues. 309,310 Despite its successful application as a reagent for the chemical modification of proteins, the irreversibility of maleimide's addition makes it impossible to regenerate the unmodified protein by controlled disassembly of the conjugate.…”

Section: Fig 20mentioning

confidence: 99%

Developments and recent advancements in the field of endogenous amino acid selective bond forming reactions for bioconjugation

2015

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Bioconjugation methodologies have proven to play a central enabling role in the recent development of biotherapeutics and chemical biology approaches. Recent endeavours in these fields shed light on unprecedented chemical challenges to attain bioselectivity, biocompatibility, and biostability required by modern applications. In this review the current developments in various techniques of selective bond forming reactions of proteins and peptides were highlighted. The utility of each endogenous amino acid-selective conjugation methodology in the fields of biology and protein science has been surveyed with emphasis on the most relevant among reported transformations; selectivity and practical use have been discussed.

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“…3C). These findings are in line with the residualizing nature of 89 Zr(IV), which stays trapped inside tumor cells after receptor-mediated endocytosis and lysosomal tracer degradation (21,22). Notably, however, the 2 protein tracers showed different levels of nonspecific accumulation, either in the thyroid ( 125 I) or in the kidney ( 89 Zr), leading to high organ-to-tumor ratios there.…”

Section: Biodistribution Studiessupporting

confidence: 57%

⁸⁹Zr-Labeled Versus ¹²⁴I-Labeled αHER2 Fab with Optimized Plasma Half-Life for High-Contrast Tumor Imaging In Vivo

et al. 2015

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Immuno-PET imaging of the tumor antigen HER2/neu allows for the noninvasive detection and monitoring of oncogene expression; such detection and monitoring are of prognostic value in patients with breast cancer. Compared with the full-size antibody trastuzumab, smaller protein tracers with more rapid blood clearance permit higher imaging contrast at earlier time points. Antigen-binding fragments (Fabs) of antibodies with moderately prolonged circulation achieved through the genetic fusion with a long, conformationally disordered chain of the natural amino acids Pro, Ala, and Ser (PASylation)-a biologic alternative to chemical conjugation with polyethylene glycol, PEG-offer a promising tracer format with improved pharmacokinetics for in vivo imaging. Recently, the transition metal radionuclide 89 Zr has attracted increasing interest for immuno-PET studies, complementing the conventional halogen radionuclide 124 I. Methods: To allow direct comparison of these 2 radioactive labels for the same protein tracer, the recombinant aHER2 Fab fused with 200 Pro, Ala, and Ser (PAS 200 ) residues was either conjugated with 124 I via an iodination reagent or coupled with deferoxamine (Df) and complexed with 89 Zr. After confirmation of the stability of both radioconjugates and quality control in vitro, immuno-PET and biodistribution studies were performed with CD1-Foxn1 nu mice bearing HER2-positive human tumor xenografts. Results: 89 Zr⋅Df-Fab-PAS 200 and 124 I-Fab-PAS 200 showed specific tumor uptake of 11 and 2.3 percentage injected dose per gram 24 h after injection, respectively; both led to high tumor-to-blood (3.6 and 4.4, respectively) and tumor-to-muscle (20 and 43, respectively) ratios. With regard to off-target accumulation, overt 124 I activity was seen in the thyroid, as expected, whereas high kidney uptake was evident for 89 Zr; the latter was probably due to glomerular filtration and reabsorption of the protein tracer in proximal tubular cells. Conclusion: Both 89 Zr-and 124 I-labeled versions of aHER2 Fab-PAS 200 allowed PET tumor imaging with high contrast. With its residualizing radiometal, the tracer 89 Zr⋅Df-Fab-PAS 200 showed better in vivo stability and higher tumor uptake.

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Enhanced Tumor Retention of a Radiohalogen Label for Site-Specific Modification of Antibodies

Cited by 38 publications

References 34 publications

Effect of Modulating FcRn Binding on Direct and Pretargeted Tumor Uptake of Full-length Antibodies

Effect of Modulating FcRn Binding on Direct and Pretargeted Tumor Uptake of Full-length Antibodies

Developments and recent advancements in the field of endogenous amino acid selective bond forming reactions for bioconjugation

⁸⁹Zr-Labeled Versus ¹²⁴I-Labeled αHER2 Fab with Optimized Plasma Half-Life for High-Contrast Tumor Imaging In Vivo

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Enhanced Tumor Retention of a Radiohalogen Label for Site-Specific Modification of Antibodies

Cited by 38 publications

References 34 publications

Effect of Modulating FcRn Binding on Direct and Pretargeted Tumor Uptake of Full-length Antibodies

Effect of Modulating FcRn Binding on Direct and Pretargeted Tumor Uptake of Full-length Antibodies

Developments and recent advancements in the field of endogenous amino acid selective bond forming reactions for bioconjugation

89Zr-Labeled Versus 124I-Labeled αHER2 Fab with Optimized Plasma Half-Life for High-Contrast Tumor Imaging In Vivo

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⁸⁹Zr-Labeled Versus ¹²⁴I-Labeled αHER2 Fab with Optimized Plasma Half-Life for High-Contrast Tumor Imaging In Vivo