First In-Human Medical Imaging with a PASylated 89Zr-Labeled Anti-HER2 Fab-Fragment in a Patient with Metastatic Breast Cancer

Richter, Antonia; Knorr, Karina; Schlapschy, Martin; Robu, Stephanie; Morath, Volker; Mendler, Claudia T; Yen, Hsi-Yu; Steiger, Katja; Kiechle, Marion; Skerra, Arne; Schwaiger, Markus

doi:10.1007/s13139-020-00638-7

Cited by 25 publications

(16 citation statements)

References 22 publications

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“…To exploit Gal3 overexpression for tumor imaging via positron emission tomography (PET) we recently developed a 89 Zr-labeled chimeric Fab-fragment derived from a well characterized rat monoclonal antibody (mAb M3/38) which demonstrated high imaging contrast in mice 9 . In accordance with earlier in vivo imaging studies of other tumor targets 10 , 11 , a Fab version with moderately prolonged plasma half-life utilizing PASylation technology turned out to result in excellent and highly specific uptake in orthotopic thyroid tumor models.…”

Section: Introductionsupporting

confidence: 74%

Effective rational humanization of a PASylated anti-galectin-3 Fab for the sensitive PET imaging of thyroid cancer in vivo

Peplau

Rose

Eichinger

et al. 2021

Sci Rep

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The lack of a non-invasive test for malignant thyroid nodules makes the diagnosis of thyroid cancer (TC) challenging. Human galectin-3 (hGal3) has emerged as a promising target for medical TC imaging and diagnosis because of its exclusive overexpression in malignant thyroid tissues. We previously developed a human-chimeric αhGal3 Fab fragment derived from the rat monoclonal antibody (mAb) M3/38 with optimized clearance characteristics using PASylation technology. Here, we describe the elucidation of the hGal3 epitope recognized by mAb M3/38, X-ray crystallographic analysis of its complex with the chimeric Fab and, based on the three-dimensional structure, the rational humanization of the Fab by CDR grafting. Four CDR-grafted versions were designed using structurally most closely related fully human immunoglobulin VH/VL regions of which one—employing the acceptor framework regions of the HIV-1 neutralizing human antibody m66—showed the highest antigen affinity. By introducing two additional back-mutations to the rodent donor sequence, an affinity toward hGal3 indistinguishable from the chimeric Fab was achieved (KD = 0.34 ± 0.02 nM in SPR). The PASylated humanized Fab was site-specifically labelled with the fluorescent dye Cy7 and applied for the immuno-histochemical staining of human tissue sections representative for different TCs. The same protein was conjugated with the metal chelator Dfo, followed by radiolabelling with 89Zr(IV). The resulting protein tracer allowed the highly sensitive and specific PET/CT imaging of orthotopic tumors in mice, which was confirmed by quantitative analysis of radiotracer accumulation. Thus, the PASylated humanized αhGal3 Fab offers clinical potential for the diagnostic imaging of TC.

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Section: Introductionsupporting

confidence: 74%

Effective rational humanization of a PASylated anti-galectin-3 Fab for the sensitive PET imaging of thyroid cancer in vivo

Peplau

Rose

Eichinger

et al. 2021

Sci Rep

Self Cite

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“…[47] A first in-human study has been recently published for the imaging of HER2-positive metastatic breast cancer. [48] PAS-Fabs can be tailored to obtain a good compromise between the long half-life of full mAbs (which have major issues such as high toxicity due to slow clearance or low tumor penetration) and the short half-lives of Fab fragments limiting their accumulation in the tumor. An anti HER2-Fab was PASylated with PAS200 then radiolabeled with zirconium-89.…”

Section: Pasmentioning

confidence: 99%

“…PET imaging using 89 Zr-Dfo-PAS 200 -HER2 Fab construct was thereby successful, well-tolerated, and represents a potential tool for diagnostic of HER2-positive breast cancer in patients. [48] The slower clearance from the blood allowed the accumulation of the tracer in both the primary tumor and metastases located in axillary lymph nodes at 24 h postinjection. However, the radiotracer was unsuccessful in detecting tumor metastases in the brain.…”

Section: Pasmentioning

confidence: 99%

Protein Engineering Strategies for Improved Pharmacokinetics

Rondon

Mahri

Morales-Yánez

et al. 2021

Adv Funct Materials

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Protein therapeutics have gained momentum in recent years and become a pillar in treating many diseases and the only choice in several ailments. Protein therapeutics are highly specific, tunable, and less toxic than conventional small drug molecules. However, reaping the full benefits of therapeutic proteins in the clinics is often hindered by issues of immunogenicity and short half-life due essentially to fast renal clearance and enzymatic degradation. Advances in polymer chemistry and protein engineering allowed overcoming some of these limitations. Strategies to prolong the half-life of proteins rely on increasing their size and stability and/or fusing them to endogenous proteins (albumin, Fc fragment of antibody) to hijack physiological pathways involved in protein recycling. On the downside, these modifications might alter therapeutic proteins structure and function. Therefore, a compromise between half-life and activity is sought. This review covers half-life extension strategies using natural and synthetic polymers as well as fusion to other proteins and sheds light on genetic engineering strategies and chemical and enzymatic reactions to achieve this goal. Promising strategies and successful applications in the clinics are highlighted. DOI: . /adfm.functions that cannot be mimicked by simple chemical compounds. Since the action of proteins is highly specific, they barely interfere with normal biological processes and cause less adverse events. Protein therapeutics are frequently derived from proteins naturally produced by the body. These agents are therefore often well tolerated and poorly immunogenic. However, proteins also suffer from significant limitations. Proteins with a molecular weight below the threshold for kidney filtration ( kDa, the size of human serum albumin) are cleared from the systemic circulation within a day. Many proteins are even cleared within a few hours or a few minutes when metabolism contributes to elimination. Therefore, therapeutic proteins need to be injected to patients several times a week (e.g., erythropoietin) or even several times a day (e.g., glucagon-like peptide-or GLP-), resulting in peaks and valleys in plasma concentrations with the alternate risks of systemic side effects and suboptimal therapeutic concentrations. Moreover, frequent administration of medication causes patient discomfort and reduces quality of life. A second limitation of proteins lies in protein immunogenicity. Foreign proteins from prokaryotes or animals might present interesting therapeutic properties in humans. However, intrinsic immunogenicity of nonhuman proteins hampers their therapeutic use in the clinic because specific antibodies generated against the foreign protein neutralize its activity and result in a loss of therapeutic efficacy over time. The unwanted immune response might even cause more serious general immune effects such as anaphylaxis.Over the last three decades, protein engineering has largely demonstrated that it can provide solutions to the limitations of natural proteins. B...

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“…Recently, [ 89 Zr]Zr-Df-Fab-PAS200 was tested in the first clinical PET study. The lesions were detectable at 24 h pi, with one of them supposedly being the previously undetected primary tumor [ 208 ]. The uptake in the kidney and hepatobiliary system dominated the images.…”

Section: Her2 Imagingmentioning

confidence: 99%

PET and SPECT Imaging of the EGFR Family (RTK Class I) in Oncology

Rinne

Orlova

Tolmachev

2021

IJMS

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The human epidermal growth factor receptor family (EGFR-family, other designations: HER family, RTK Class I) is strongly linked to oncogenic transformation. Its members are frequently overexpressed in cancer and have become attractive targets for cancer therapy. To ensure effective patient care, potential responders to HER-targeted therapy need to be identified. Radionuclide molecular imaging can be a key asset for the detection of overexpression of EGFR-family members. It meets the need for repeatable whole-body assessment of the molecular disease profile, solving problems of heterogeneity and expression alterations over time. Tracer development is a multifactorial process. The optimal tracer design depends on the application and the particular challenges of the molecular target (target expression in tumors, endogenous expression in healthy tissue, accessibility). We have herein summarized the recent preclinical and clinical data on agents for Positron Emission Tomography (PET) and Single Photon Emission Tomography (SPECT) imaging of EGFR-family receptors in oncology. Antibody-based tracers are still extensively investigated. However, their dominance starts to be challenged by a number of tracers based on different classes of targeting proteins. Among these, engineered scaffold proteins (ESP) and single domain antibodies (sdAb) show highly encouraging results in clinical studies marking a noticeable trend towards the use of smaller sized agents for HER imaging.

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First In-Human Medical Imaging with a PASylated 89Zr-Labeled Anti-HER2 Fab-Fragment in a Patient with Metastatic Breast Cancer

Cited by 25 publications

References 22 publications

Effective rational humanization of a PASylated anti-galectin-3 Fab for the sensitive PET imaging of thyroid cancer in vivo

Effective rational humanization of a PASylated anti-galectin-3 Fab for the sensitive PET imaging of thyroid cancer in vivo

Protein Engineering Strategies for Improved Pharmacokinetics

PET and SPECT Imaging of the EGFR Family (RTK Class I) in Oncology

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