Clinical Trials of Functional Nucleic Acids: Antisense Oligonucleotides and Aptamers

This chapter describes how functional nucleic acids, such as aptamers, antisense oligonucleotides (ASOs), small interfering (si) RNAs, and ribozymes are considered by some researchers as valuable tools to develop therapeutic agents. They have not been particularly fast in reaching the market as medicines, due to endogenous barriers to extracellular trafficking and cellular uptake of nucleic acids and their inherent instability when applied in vivo. However, research carried out by the nucleic acid engineering community and pharmaceutical companies to circumvent these obstacles has led to the approval of a few aptamers and ASOs as drugs. Nucleic acid therapeutics are usually administered locally to diseased tissue. The drug candidates currently in clinical trials commonly use the same administration methods as previously licensed nucleic acid therapeutics. These administration techniques carry their own safety risks and advantages. In this article, the present state is discussed and prospective options for the use ASOs and aptamers as drugs are listed.