Effect of Inter-Domain Linker Composition on Biodistribution of ABD-Fused Affibody-Drug Conjugates Targeting HER2

Tianqi Xu; Jie Zhang; Maryam Oroujeni; Maria S Tretyakova; Vitalina Bodenko; Mikhail V Belousov; Anna Orlova; Vladimir Tolmachev; Anzhelika Vorobyeva; Torbjörn Gräslund

doi:10.3390/pharmaceutics14030522

Effect of Inter-Domain Linker Composition on Biodistribution of ABD-Fused Affibody-Drug Conjugates Targeting HER2

Pharmaceutics. 2022 Feb 26;14(3):522. doi: 10.3390/pharmaceutics14030522.

Authors

Tianqi Xu¹, Jie Zhang², Maryam Oroujeni^{1

3}, Maria S Tretyakova^{4

5}, Vitalina Bodenko⁴, Mikhail V Belousov^{6

7}, Anna Orlova^{4

8}, Vladimir Tolmachev^{1

4}, Anzhelika Vorobyeva^{1

4}, Torbjörn Gräslund²

Affiliations

¹ Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden.
² Department of Protein Science, KTH Royal Institute of Technology, Roslagstullsbacken 21, 114 17 Stockholm, Sweden.
³ Department of Science and Development, Affibody AB, 171 65 Solna, Sweden.
⁴ Research Centrum for Oncotheranostics, Research School of Chemistry and Applied Biomedical Sciences, Tomsk Polytechnic University, 634050 Tomsk, Russia.
⁵ Cancer Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, 634009 Tomsk, Russia.
⁶ Department of Pharmaceutical Analysis, Siberian State Medical University, Ministry of Health of the Russian Federation, 634050 Tomsk, Russia.
⁷ Research School of Chemistry and Applied Biomedical Sciences, National Research Tomsk Polytechnic University, 634050 Tomsk, Russia.
⁸ Department of Medicinal Chemistry, Uppsala University, 751 23 Uppsala, Sweden.

Abstract

Targeted drug conjugates based on Affibody molecules fused to an albumin-binding domain (ABD) for half-life extension have demonstrated potent anti-tumor activity in preclinical therapeutic studies. Furthermore, optimization of their molecular design might increase the cytotoxic effect on tumors and minimize systemic toxicity. This study aimed to investigate the influence of length and composition of a linker between the human epidermal growth factor receptor 2 (HER2)-targeted affibody molecule (Z_HER2:2891) and the ABD domain on functionality and biodistribution of affibody-drug conjugates containing a microtubulin inhibitor mertansin (mcDM1) (AffiDCs). Two conjugates, having a trimeric (S₃G)₃ linker or a trimeric (G₃S)₃ linker were produced, radiolabeled with ^99mTc(CO)₃, and compared side-by-side in vitro and in vivo with the original Z_HER2:2891-G₄S-ABD-mcDM1 conjugate having a monomeric G₄S linker. Both conjugates with longer linkers had a decreased affinity to HER2 and mouse and human serum albumin in vitro, however, no differences in blood retention were observed in NMRI mice up to 24 h post injection. The use of both (S₃G)₃ and (G₃S)₃ linkers reduced liver uptake of AffiDCs by approximately 1.2-fold compared with the use of a G₄S linker. This finding provides important insights into the molecular design for the development of targeted drug conjugates with reduced hepatic uptake.

Keywords: AffiDC; DM1; HER2; SKOV3; affibody drug conjugate; affibody molecule; albumin binding domain; emtansine; human epidermal growth factor receptor 2.

Abstract

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