Argos Therapeutics Presents Positive Phase 1 Safety Data for its Arcelis(TM) Platform in HIV at Keystone Symposia.

-Additional Presentation on Methods to Improve Antigen Expression in Immunotherapies-

DURHAM, N.C. -- Argos Therapeutics today announced the presentation of positive safety and feasibility data from a Phase 1 clinical trial of AGS-004 in HIV-infected adults in combination with antiretroviral therapy (ART). AGS-004 is an adaptation of the Company's Arcelis[TM] technology, a personalized, RNA-loaded dendritic cell-based immunotherapy that is perfectly matched to each patient's unique viral burden. Researchers also presented an abstract describing the Company's method of RNA production which improves antigen expression in dendritic cells. These data were presented at the Keystone Symposia Conference on HIV Vaccines, held March 27 - April 1 in Banff, Alberta.

The Phase 1 trial was conducted at McGill University Health Centre in Montreal by Jean-Pierre Routy, M.D. "Initial data revealed no serious adverse events," said Dr. Routy. "Mild adverse events observed were consistent with immune response induction and typical of similar therapies." In addition, no spikes in viral load, significant changes in CD4 or CD8 cell counts, or manifestations of autoimmunity were observed during or after injections. Argos also successfully demonstrated manufacturing feasibility and production consistency of AGS-004.

"We are encouraged by the favorable safety and tolerability profile of AGS-004 in this trial, as well as the application of our Arcelis[TM] technology to creating immunotherapies to treat viral disease," said John Bonfiglio, Ph.D., President and CEO of Argos. "Argos looks forward to presenting the full Phase 1 trial results, including immune response data, later this year. The data generated thus far support further investigation of this promising immunotherapy candidate in HIV and, therefore, we are in the process of initiating a Phase 2a trial of AGS-004."

In a second presentation during a poster session at the meeting, Argos researchers discussed the benefits of an approach for post-transcriptionally capping HIV RNAs to enhance antigen expression in dendritic cells. This method may have broad applicability for immunotherapies utilizing RNA as a vehicle for antigen delivery. The post-transcriptional capping method, which uses a vaccinia virus capping enzyme, offers advantages over the commonly used method of co-transcriptional capping. These benefits include close to 100% capping efficiency, significantly greater RNA yield, and elevated levels of protein expression in dendritic cells.

The Phase 1 data abstract titled, "A Phase 1 safety and feasibility study of autologous dendritic cell therapy in ART treated HIV-1-infected subjects," was presented on March 30. This abstract was authored by: Jean-Pierre Routy, M.D.; M.R. Boulassel; C. Landry; Y. Yassien-Diab; R. Antar; Irina Tcherepanova, Ph.D.; Donald Healey, Ph.D.; Frederick Miesowicz, Ph.D.; Charles A. Nicolette, Ph.D.; Lothar Finke, M.D.; and R.P. Sekaly, Ph.D.

The abstract titled, "Post transcriptionally capped HIV RNAs confer higher antigen expression level in the DCs," was presented on March 30. This abstract was authored by: Irina Tcherepanova, Ph.D.; A. Starr; A. Raney; D. Calderhead, Ph.D.; J. Horvatinovich; Donald Healey, Ph.D.; and Charles A. Nicolette, Ph.D.

About the AGS-004 Phase 1 Trial in HIV

Ten patients with HIV who have achieved durable viral suppression with ART were enrolled in the Phase 1 trial. The primary study objective is to evaluate patient-specific anti-viral responses to the AGS-004 immunotherapeutic following four doses over four months. Secondary trial objectives are to evaluate safety, additional immune induction profiles, and the feasibility of production of AGS-004. The development of AGS-004 is part of Argos' broad collaboration with Kirin Pharma Company, Ltd.

RNA-loaded Dendritic Cell Technology

Arcelis[TM] is Argos' proprietary technology for personalizing RNA-loaded dendritic cell immunotherapies for HIV, other infectious diseases, and cancer. This platform is based on optimizing a patient's own (autologous) dendritic cells to trigger a pathogen- or tumor-specific immune response. To address the challenge of the unique genetic profile of each patient's disease and the genetic mutations of that disease, Argos loads the autologous dendritic cells with a sample of messenger RNA ("mRNA") isolated from their disease. Through this process, dendritic cells can potentially prime immune responses to the entire antigenic repertoire, resulting in an immunotherapeutic that is customized to the patient's specific disease.

About Argos Therapeutics, Inc.

Argos Therapeutics is developing breakthrough immunotherapies that target the unique features of a patient's disease. This new generation of personalized cancer and infectious disease therapeutics, created using the Company's "Arcelis" technology, trains the immune system to recognize and attack the disease. Argos' scientific leadership in RNA-loaded dendritic cells and advanced manufacturing processes provide a platform to tackle virtually all forms of cancers and infectious diseases. www.argostherapeutics.com

Argos is a private biotechnology company headquartered in Research Triangle Park, NC. The Company has clinical trial programs in cancer and human immunodeficiency virus (HIV) and has an ongoing co-development and commercialization alliance with Kirin Pharma Company, Ltd.