Advances in oligonucleotide drug delivery

Oligonucleotide-based drugs have the potential to treat or manage a wide range of diseases. However, the widespread application of such therapies has been hampered by the difficulty in achieving efficient delivery to extrahepatic tissues. Here, Roberts et al. overview oligonucleotide-based drug platforms and assess approaches being employed to improve their delivery. Oligonucleotides can be used to modulate gene expression via a range of processes including RNAi, target degradation by RNase H-mediated cleavage, splicing modulation, non-coding RNA inhibition, gene activation and programmed gene editing. As such, these molecules have potential therapeutic applications for myriad indications, with several oligonucleotide drugs recently gaining approval. However, despite recent technological advances, achieving efficient oligonucleotide delivery, particularly to extrahepatic tissues, remains a major translational limitation. Here, we provide an overview of oligonucleotide-based drug platforms, focusing on key approaches - including chemical modification, bioconjugation and the use of nanocarriers - which aim to address the delivery challenge.