Intracellular delivery of therapeutic oligonucleotides in pH-sensitive and cationic liposomes

Antisense oligonucleotide drugs and other similar drugs have much to offer as potential therapeutic agents, and as tools in genomics and proteomics. These drugs may be useful in the treatment of viral infections, cancer, restenosis, rheumatoid arthritis, and allergic disorders. The current clinical status of antisense therapeutics is shown in Table 1. Despite the extensive work with antisense oligonucleotides to date, the only antisense-based product that is approved for use is Vitravene (fomivirsen) against cytomegalovirus (CMV) retinitis (1,2).