Toxicity and Pharmacokinetic Profile for Single-Dose Injection of ABY-029: a Fluorescent Anti-EGFR Synthetic Affibody Molecule for Human Use

Abstract

Purpose ABY-029, a synthetic Affibody peptide, Z03115-Cys, labeled with a near-infrared fluorophore, IRDye® 800CW, targeting epidermal growth factor receptor has been produced under Good Manufacturing Practices for an FDA approved first-in-use human study during surgical resection of glioma, as well as other tumors. Here, the pharmacology, phototoxicity, receptor activity and biodistribution studies of ABY-029 were completed in rats, prior to the intended human use. Procedures Male and female Sprague-Dawley rats were administered a single intravenous dose of varying concentrations (0, 245, 2449, and 24,490 µg/kg corresponding to 10X, 100X, and 1000X an equivalent human microdose level) of ABY-029 and observed for up to 14 days. Histopathological assessment of organs and tissues, clinical chemistry and hematology were performed. In addition, pharmacokinetic clearance, and biodistribution of ABY-029 were studied in sub-groups of the animals. Phototoxicity and ABY-029 binding to human and rat EGFR were assessed in cell culture and on immobilized receptors, respectively. Results Histopathological assessment, and hematological and clinical chemistry analysis demonstrated that single-dose ABY-029 produced no pathological evidence of toxicity at any dose level. No phototoxicity was observed in EGFR positive and negative glioma cell lines. Binding strength and pharmacokinetics of the anti-EGFR Affibody molecules were retained after labeling with the dye. Conclusion Based on the successful safety profile of ABY-029, the 1000X human microdose 24.5 mg/kg was identified as the no observed adverse effect level (NOAEL) following intravenous administration. Conserved binding strength and no observed light toxicity also demonstrated ABY-029 safety for human use.

Preclinical imaging of epidermal growth factor receptor with ABY‐029 in soft‐tissue sarcoma for fluorescence‐guided surgery and tumor detection

“…The production of Good Laboratory Practices ABY‐029 has been described previously . Stock solutions of 0.42 mg/mL were obtained from the University of Alabama at Birmingham Vector Production Facility and were further diluted in sterile PBS to a concentration of 4.98 μM for experimental administration.…”

“…Fluorescence‐guided surgery (FGS) is a rapidly growing field. 5‐Aminolevulinic acid/protoporphyrin IX was recently approved for clinical use, and numerous protein‐targeted and activatable fluorophores are in preclinical and phase 0/1 clinical trials . We have developed and begun testing ABY‐029, an IRDye 800CW‐labeled anti‐epidermal growth factor receptor (EGFR) Affibody ® molecule.…”

“…Affibody ® molecules are small, engineered peptides that can be optimized and adapted for various imaging applications and therapy . ABY‐029 is approved as an exploratory investigational new drug (eIND application 122681) by the US Federal Drug Administration and is currently being tested for FGS in phase 0 studies of several cancers at microdose administration levels . The main advantage of ABY‐029 as compared with larger antibody‐based targeting agents is that ABY‐029 has a significantly shorter plasma half‐life, measured in minutes to several hours, as compared with days, which would allow for administration and surgery to occur on the same day .…”

“…5-Aminolevulinic acid/protoporphyrin IX was recently approved for clinical use, and numerous protein-targeted and activatable fluorophores are in preclinical and phase 0/1 clinical trials. [1][2][3][4][5][6][7][8][9][10] We have developed and begun testing ABY-029, an IRDye 800CW-labeled anti-epidermal growth factor receptor (EGFR) Affibody ® molecule. Affibody ® molecules are small, engineered peptides that can be optimized and adapted for various imaging…”

“…11 ABY-029 is approved as an exploratory investigational new drug (eIND application 122681) by the US Federal Drug Administration and is currently being tested for FGS in phase 0 studies of several cancers at microdose administration levels. 1 The main advantage of ABY-029 as compared with larger antibody-based targeting agents is that ABY-029 has a significantly shorter plasma half-life, measured in minutes to several hours, as compared with days, which would allow for administration and surgery to occur on the same day. 1,2,[12][13][14][15][16] In addition, ABY-029 is not anticipated to cause any pharmacological response, given that no immunogenic side effects were observed during toxicity testing using doses equivalent to 1000 times the human microdose level.…”