On October 21st, Argos Therapeutics announced the positive results of a Phase 2a trial of AGS-004, a personalized immunotherapy candidate, during two presentations at the AIDS Vaccine 2009 conference in Paris.

AGS-004 is a therapeutic vaccine, which works by stimulating an HIV-infected individual’s immune cells to trigger an immune response in order to help the body maintain better control of the infection. This vaccine is unique because Argos individualizes the immune system cells of each infected individual by adding mRNA, or fragments of DNA, isolated from the individual’s disease.

The first presentation showed data from 16 HIV-positive individuals who underwent AGS-004 treatment for a 12-week structured treatment interruption (STI) from antiretroviral therapy (ART). Despite the break from ART, 13 of the 16 participants showed a decrease of viral load, the amount of virus in the body. Additionally, AGS-004 had a favorable safety profile, with no reports of side effects during STI.

A second presentation involving the same group of study participants showed an increase in CD8 cell responses after vaccination. CD8 cell responses are believed to be indicative of the immune system’s response to viral infection.

Because of these positive results, Argos is planning on conducting a Phase 2b trial during 2010. This study is the first successful one involving an immunotherapy candidate, and if proven to be effective in the upcoming trial, it could lead to a new treatment plan for HIV.

For more information, please see Argos’ news release.