Oligonucleotides to the (Gene) Rescue: FDA Approvals 2017-2019.

Four decades have passed since oligonucleotides were first used to manipulate gene expression. There were few FDA approvals prior to 2016, mostly of drugs that eventually exhibited poor performance in the market. The aura of their younger siRNA relatives had also faded during the past 15 years. However, several FDA approvals have occurred in the past 4 years, restoring hope that a new era has dawned in oligonucleotide/siRNA clinical therapeutics. Here, we review the field of oligonucleotide therapeutics and provide an update on FDA approvals of oligonucleotides from 2017 until the second quarter of 2019. We take into consideration the ethical issues looming over the still somewhat limited efficacy of these molecules, the toxicity of treatment, and the exorbitant cost of these therapeutic agents, which limits accessibility for many.