Title
Evaluation of the therapeutic potential of a HER3-binding affibody construct TAM-HER3 in comparison with a monoclonal antibody, seribantumab
Author
Anna Orlova, Tarek Z Bass, Sara S. Rinne, Charles Dahlsson Leitao, Maria Rosestedt, Christina Atterby, Lindvi Gudmundsdotter, Fredrik Y. Frejd, John Löfblom, Vladimir Tolmachev, Sefan Stahl
Year
2018
Journal
Molecular Pharmaceutics
Abstract
Human epidermal growth factor receptor type 3 (HER3) is recognized to be involved in resistance to HER-targeting therapies. A number of HER3-targeting monoclonal antibodies are under clinical investigation as potential cancer therapeutics. Smaller high-affinity scaffold proteins are attractive non-Fc containing alternatives to antibodies. A previous study indicated that anti-HER3 affibody molecules could delay the growth of xenografted HER3-positive tumors. Here, we designed a second-generation HER3-targeting construct (TAM-HER3), containing two HER3-specific affibody molecules bridged by an albumin-binding domain (ABD) for extension of blood circulation. Receptor blocking activity was demonstrated in vitro. In mice bearing BxPC-3 xenografts, the therapeutic efficacy of TAM-HER3 was compared to the HER3-specific monoclonal antibody seribantumab (MM-121). TAM-HER3 inhibited heregulin-induced phosphorylation in a panel of HER3-expressing cancer cells and was found to be equally potent as seribantumab in terms of therapeutic efficacy in vivo and with a similar safety profile. Median survival times were 60 d for TAM-HER3, 54 d for seribantumab, and 41 d for the control group. No pathological changes were observed in cytopathological examination. The multimeric HER3-binding affibody molecule in fusion to ABD seems promising for further evaluation as candidate therapeutics for treatment of HER3-overexpressing tumors.
Instrument
J-810
Keywords
Circular dichroism, Secondary structure, Thermal stability, Thermodynamics, Protein folding, Biochemistry, Pharmaceutical