Strategies for In Vivo Screening and Mitigation of Hepatotoxicity Associated with Antisense Drugs

Piotr J Kamola; Klio Maratou; Paul A Wilson; Kay Rush; Tanya Mullaney; Tom McKevitt; Paula Evans; Jim Ridings; Probash Chowdhury; Aude Roulois; Ann Fairchild; Sean McCawley; Karen Cartwright; Nigel J Gooderham; Timothy W Gant; Kitty Moores; Stephen A Hughes; Mark R Edbrooke; Kenneth Clark; Joel D Parry

doi:10.1016/j.omtn.2017.07.003

Strategies for In Vivo Screening and Mitigation of Hepatotoxicity Associated with Antisense Drugs

Mol Ther Nucleic Acids. 2017 Sep 15:8:383-394. doi: 10.1016/j.omtn.2017.07.003. Epub 2017 Jul 8.

Authors

Piotr J Kamola¹, Klio Maratou², Paul A Wilson², Kay Rush³, Tanya Mullaney³, Tom McKevitt³, Paula Evans³, Jim Ridings³, Probash Chowdhury³, Aude Roulois³, Ann Fairchild³, Sean McCawley³, Karen Cartwright³, Nigel J Gooderham⁴, Timothy W Gant⁵, Kitty Moores², Stephen A Hughes², Mark R Edbrooke², Kenneth Clark², Joel D Parry³

Affiliations

¹ Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK; GlaxoSmithKline R&D, Ware SG12 0DP, UK; GlaxoSmithKline R&D, Stevenage SG1 2NY, UK; Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Harwell Science and Innovation Campus, Oxfordshire OX11 0RQ, UK. Electronic address: piotr.kamola@riken.jp.
² GlaxoSmithKline R&D, Stevenage SG1 2NY, UK.
³ GlaxoSmithKline R&D, Ware SG12 0DP, UK.
⁴ Department of Surgery and Cancer, Imperial College London, London SW7 2AZ, UK.
⁵ Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Harwell Science and Innovation Campus, Oxfordshire OX11 0RQ, UK.

Abstract

Antisense oligonucleotide (ASO) gapmers downregulate gene expression by inducing enzyme-dependent degradation of targeted RNA and represent a promising therapeutic platform for addressing previously undruggable genes. Unfortunately, their therapeutic application, particularly that of the more potent chemistries (e.g., locked-nucleic-acid-containing gapmers), has been hampered by their frequent hepatoxicity, which could be driven by hybridization-mediated interactions. An early de-risking of this liability is a crucial component of developing safe, ASO-based drugs. To rank ASOs based on their effect on the liver, we have developed an acute screen in the mouse that can be applied early in the drug development cycle. A single-dose (3-day) screen with streamlined endpoints (i.e., plasma transaminase levels and liver weights) was observed to be predictive of ASO hepatotoxicity ranking established based on a repeat-dose (15 day) study. Furthermore, to study the underlying mechanisms of liver toxicity, we applied transcriptome profiling and pathway analyses and show that adverse in vivo liver phenotypes correlate with the number of potent, hybridization-mediated off-target effects (OTEs). We propose that a combination of in silico OTE predictions, streamlined in vivo hepatotoxicity screening, and a transcriptome-wide selectivity screen is a valid approach to identifying and progressing safer compounds.

Keywords: ASOs; LNA; OTEs; RNArcher; antisense oligonucleotides; gene silencing; hepatotoxicity; locked nucleic acids; off-target effects; selectivity.