Data on Argos Therapeutics' Phase 2a AGS-004 immunotherapy trial presented at Banff HIV Vaccines meeting

Argos Therapeutics today announced the presentation of data from the Phase 2a trial of AGS-004, providing information on rebound viral genetic diversity in HIV patients treated with the personalized immunotherapy following antiretroviral therapy (ART) interruption. The data were discussed in a poster session at the Keystone Symposia Global Health Series HIV Vaccines meeting, held March 21-26, 2010 in Banff, Canada. AGS-004 is a product of the Company’s Arcelis™ technology, and it is a personalized, RNA-loaded, dendritic cell-based immunotherapy that is perfectly matched to each patient’s unique HIV viral burden. Argos recently reported interim data from the Phase 2a trial, demonstrating viral load control in the absence of antiretroviral therapy and robust immune responses to a diverse set of HIV antigens. Argos plans to initiate a Phase 2b trial in the first half of 2010.

“Study of Rebound Virus Genetic Diversity in Subjects Treated with Autologous DC-based (AGS-004) Immunotherapy After ART Interruption”

AGS-004 utilizes autologous RNA encoding HIV antigens Gag, Vpr, Rev and Nef (GVRN). Argos’ RNA technology is designed to amplify a complex mixture of autologous mutated HIV quasispecies, specific to each patient, from plasma collected prior to ART initiation. In the Phase 2a trial, patients received four doses of AGS-004 during ART treatment, followed by two doses after ART interruption. Samples of post-AGS-004 plasma were then collected during the ART interruption from subjects with detectable viral load. Genetic evolution of the virus was analyzed through sequencing at least 10 individual clones of each GVRN gene following AGS-004 treatment, and comparing to those isolated from the pre-treatment sample. As expected, in some subjects, the post-AGS-004 samples revealed a shift in viral diversity, indicating that the remaining virus did mutate over the course of treatment.

Charles Nicolette, Ph.D., Chief Scientific Officer and Vice President of Research and Development of Argos Therapeutics, said: “We believe that one component of the method-of-action for AGS-004 is that it forces the virus to mutate in response to immune pressure. The more the virus mutates, the less able to replicate and weaker it becomes. Additionally, the diversity of the mutations is generally much narrower following AGS-004 treatment. We believe that this less robust residual virus is a direct result of the broad immune response induced by AGS-004. These observations may explain the low viral load levels reported for patients enrolled in the Phase 2a trial of AGS-004. We are excited to generate controlled data for AGS-004 in the Phase 2b trial, which we anticipate will commence soon.”