Abstract
Twelve years ago, the author introduced the situation of research and development of nucleic
acid/gene medicines at the Annual Meeting of the Pharmaceutical Society of Japan. It was
anticipated that the main R&D theme in industries would be shifted to nucleic acid medicines
more, because nucleic acid medicines have some advantages compared to plasmid DNAs for gene
therapy which are used with liposomes and so on, in terms of chemical modification, transfection
efficiency, chemical stability, and etc. The current situation after 12 years is different from the
above prediction. In fact, there are some nucleic acid medicines such as antisense, siRNA, etc. on
the market as exactly expected. While at the same time, seven kinds of gene therapy medicines
using virus vectors have been also launched out during 5 years, which is contrary to the author's
prediction. The contribution of DDS (drug delivery system) technologies seems to be still low, but
in the near future DDS will be undoubtedly needed in order to improve the efficacy and safety of
nucleic acid/gene medicines. Exosomes, which recently receive a lot of attention, may give us
some kinds of suggestions for the issue resolution.
