Demonstrates Dose-Proportional Neutralization of Interferon-Alpha Activity Durham, NC– June 7, 2012 — Argos Therapeutics Inc., a biopharmaceutical company focused on the development and commercialization of fully personalized and novel immunotherapies, presented positive Phase 1a clinical data for its monoclonal antibody-based therapy, AGS-009, for the treatment of systemic lupus erythematosus (lupus) at the 2012 European League Against Rheumatism (EULAR) Congress in Berlin. In addition to being safe and generally well tolerated by patients, AGS-009 demonstrated a dose-proportional shift toward normalization of the genes regulated by its target, human interferon-alpha (IFN-a). High plasma levels of this important cell signaling molecule are correlated strongly to lupus disease severity, and IFN-a has been implicated in a number of other autoimmune pathways. “There have been few advances in lupus treatment in the past fifty years, and AGS-009 has the potential to meet this significant unmet medical need,” said Charles Nicolette, Ph.D., Chief Scientific Officer and Vice President of Research and Development of Argos Therapeutics. “These early clinical results are encouraging because they validate AGS-009´s intended mechanism of action in the disease setting. We look forward to advancing AGS-009 further in the clinic where we are confident that its ability to neutralize IFN-a activity will translate into clinical benefit for patients.” Jeff Abbey, Chief Executive Officer of Argos Therapeutics, said, “We are encouraged by the positive Phase 1a data presented at EULAR. As we continue to engage in active partnering discussions for our AGS-009 program, we are preparing to advance AGS-009 along the clinical pathway.” In the Phase 1a study, all patients who received AGS-009 trended toward normal IFN-a signatures after only a single dose, whereas none of the patients receiving placebo showed a similar shift. Furthermore, the magnitude of the shift toward normal IFN-a signatures was dose-proportional, which strongly suggests that AGS-009 neutralizes IFN-a effectively in the blood of lupus patients. Peak plasma levels of AGS-009 were proportional to the doses administered, and the half-life remained relatively constant at 11-20 days across the dose groups, which is consistent with the half-life reported for other monoclonal antibodies. The Phase 1a trial was a multicenter, randomized, double blind, placebo-controlled single dose escalation study. Twenty five patients with mild to moderate lupus, based on their disease activity index, were randomized at a ratio of 3:1 within each cohort to receive a single intravenous infusion of AGS-009 at 0.01, 0.1, 0.6, 3, 10 and 30 mg/kg or placebo. Patients were monitored for safety based on adverse events, physical examinations and clinical laboratory tests. Serum samples were collected longitudinally before and after the drug administration for a period of 85 days to evaluate pharmacokinetics. About the Arcelis™ Technology Arcelis is a fully personalized, active immunotherapy technology platform that captures all antigens, including mutated and variant antigens that are specific to each patient´s disease. It has been shown to overcome immunosuppression by producing a durable memory T-cell response without adjuvants that are associated with toxicity. The Arcelis technology platform can be leveraged to manufacture personalized therapies for any cancer or infectious disease. The Arcelis™ technology integrates readily into current treatment paradigms, using only a small tumor or blood sample and the patient´s own dendritic cells, which are derived and optimized following a single leukapheresis procedure. The proprietary technology uses RNA isolated from the patient disease sample to program the dendritic cells to target the entire disease-antigen repertoire. The activated, antigen-loaded dendritic cells are then formulated into the patient´s plasma and administered as a single injection under the skin to produce the desired patient-specific immune response. The Arcelis™ technology platform also overcomes many of the manufacturing and commercialization challenges that have impeded other cancer immunotherapies. Automated processes allow a single facility to serve all of North America and can be used to treat any cancer or infectious disease with the same manufacturing process and equipment. About Argos Therapeutics, Inc. Argos Therapeutics is a biopharmaceutical company focused on the development and commercialization of fully personalized immunotherapies for the treatment of cancer and infectious diseases using its Arcelis™ technology platform. Argos’ most advanced product candidate, AGS-003, has initiated a Phase 3 study for the treatment of mRCC, and the Company plans to complete enrollment of its Phase 2b study of AGS-004 for the treatment of HIV in late 2012. Argos also recently completed a successful Phase 1a study of AGS-009 in patients with lupus.