TY - JOUR
T1 - Incorporation of a hydrophilic spacer reduces hepatic uptake of her2-targeting affibody–dm1 drug conjugates
AU - Ding, Haozhong
AU - Altai, Mohamed
AU - Rinne, Sara S.
AU - Vorobyeva, Anzhelika
AU - Tolmachev, Vladimir
AU - Gräslund, Torbjörn
AU - Orlova, Anna
N1 - Funding Information:
Funding: This research was funded by the Swedish Cancer Society (grants CAN 2018/824 (T.G.), CAN 2017/425 (A.O.) and CAN2015/350 (V.T.)), the Swedish Research Council (2015-02509 (A.O.) and 2015-02353 (V.T.)), an ESCAPE Cancer grant from the Swedish Agency for Innovation VINNOVA (2016-04060 and 2019-00104 A.O.), and the Swedish Society for Medical Research (M.A.).
Publisher Copyright:
© 2019 by the authors.
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2019/8
Y1 - 2019/8
N2 - Affibody molecules are small affinity-engineered scaffold proteins which can be engineered to bind to desired targets. The therapeutic potential of using an affibody molecule targeting HER2, fused to an albumin-binding domain (ABD) and conjugated with the cytotoxic maytansine derivate MC-DM1 (AffiDC), has been validated. Biodistribution studies in mice revealed an elevated hepatic uptake of the AffiDC, but histopathological examination of livers showed no major signs of toxicity. However, previous clinical experience with antibody drug conjugates have revealed a moderate- to high-grade hepatotoxicity in treated patients, which merits efforts to also minimize hepatic uptake of the AffiDCs. In this study, the aim was to reduce the hepatic uptake of AffiDCs and optimize their in vivo targeting properties. We have investigated if incorporation of hydrophilic glutamate-based spacers adjacent to MC-DM1 in the AffiDC, (ZHER2:2891)2–ABD–MC-DM1, would counteract the hydrophobic nature of MC-DM1 and, hence, reduce hepatic uptake. Two new AffiDCs including either a triglutamate–spacer–, (ZHER2:2891)2–ABD–E3–MC-DM1, or a hexaglutamate–spacer–, (ZHER2:2891)2–ABD–E6–MC-DM1 next to the site of MC-DM1 conjugation were designed. We radiolabeled the hydrophilized AffiDCs and compared them, both in vitro and in vivo, with the previously investigated (ZHER2:2891)2–ABD–MC-DM1 drug conjugate containing no glutamate spacer. All three AffiDCs demonstrated specific binding to HER2 and comparable in vitro cytotoxicity. A comparative biodistribution study of the three radiolabeled AffiDCs showed that the addition of glutamates reduced drug accumulation in the liver while preserving the tumor uptake. These results confirmed the relation between DM1 hydrophobicity and liver accumulation. We believe that the drug development approach described here may also be useful for other affinity protein-based drug conjugates to further improve their in vivo properties and facilitate their clinical translatability.
AB - Affibody molecules are small affinity-engineered scaffold proteins which can be engineered to bind to desired targets. The therapeutic potential of using an affibody molecule targeting HER2, fused to an albumin-binding domain (ABD) and conjugated with the cytotoxic maytansine derivate MC-DM1 (AffiDC), has been validated. Biodistribution studies in mice revealed an elevated hepatic uptake of the AffiDC, but histopathological examination of livers showed no major signs of toxicity. However, previous clinical experience with antibody drug conjugates have revealed a moderate- to high-grade hepatotoxicity in treated patients, which merits efforts to also minimize hepatic uptake of the AffiDCs. In this study, the aim was to reduce the hepatic uptake of AffiDCs and optimize their in vivo targeting properties. We have investigated if incorporation of hydrophilic glutamate-based spacers adjacent to MC-DM1 in the AffiDC, (ZHER2:2891)2–ABD–MC-DM1, would counteract the hydrophobic nature of MC-DM1 and, hence, reduce hepatic uptake. Two new AffiDCs including either a triglutamate–spacer–, (ZHER2:2891)2–ABD–E3–MC-DM1, or a hexaglutamate–spacer–, (ZHER2:2891)2–ABD–E6–MC-DM1 next to the site of MC-DM1 conjugation were designed. We radiolabeled the hydrophilized AffiDCs and compared them, both in vitro and in vivo, with the previously investigated (ZHER2:2891)2–ABD–MC-DM1 drug conjugate containing no glutamate spacer. All three AffiDCs demonstrated specific binding to HER2 and comparable in vitro cytotoxicity. A comparative biodistribution study of the three radiolabeled AffiDCs showed that the addition of glutamates reduced drug accumulation in the liver while preserving the tumor uptake. These results confirmed the relation between DM1 hydrophobicity and liver accumulation. We believe that the drug development approach described here may also be useful for other affinity protein-based drug conjugates to further improve their in vivo properties and facilitate their clinical translatability.
KW - Affibody
KW - DM1
KW - Drug conjugates
KW - Hepatic uptake
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U2 - 10.3390/cancers11081168
DO - 10.3390/cancers11081168
M3 - Article
AN - SCOPUS:85071755584
VL - 11
JO - Cancers
JF - Cancers
SN - 2072-6694
IS - 8
M1 - 1168
ER -