The successes and failures of HIV drug discovery.
BACKGROUND
To date, several anti-human immunodeficiency virus (HIV) drugs, including reverse transcriptase inhibitors and protease inhibitors, have been developed and used clinically for the treatment of patients infected with HIV. Recently, novel drugs have been discovered which have different mechanisms of action from those of the above inhibitors, including entry inhibitors and integrase (IN) inhibitors; the clinical use of three of these inhibitors has been approved. Other inhibitors are still in development.


METHODS
This review article summarizes the history of the development of anti-HIV drugs and also focuses on successes in the development of these entry and IN inhibitors, along with looking at exploratory approaches for the development of other inhibitors.


CONCLUSIONS
Currently used highly active antiretroviral therapy can be subject to a loss of efficacy, due to the emergence of multi-drug resistant (MDR) strains; a change of regimens of the drug combination is required to combat this, along with careful monitoring of the virus and CD4 in the blood, by methods such as cellular tropism testing. In such a situation, entry inhibitors such as CCR5/CXCR4 antagonists, CD4 mimics, fusion inhibitors and IN inhibitors might be optional agents for an expansion of the drug repertoire available to patients at all stages of HIV infection.
Institute of Biomaterials and Bioengineering ,  Tokyo Medical and Dental University, Chiyoda-ku, Tokyo 101-0062 ,  Japan   +81 3 5280 8036 ;  +81 3 5280 8039 ;  tamamura.mr@tmd.ac.jp ;  nomura.mr@tmd.ac.jp.
Chie
C
Hashimoto
Tomohiro
T
Tanaka
Tetsuo
T
Narumi
Wataru
W
Nomura
Hirokazu
H
Tamamura