Argos Therapeutics announced today that its Arcelis immunotherapy for the treatment of HIV, AGS-004, demonstrated positive outcomes with the primary endpoint of viral load control and a favorable safety and immunogenicity profile in a final analysis of a Phase 2a clinical trial. Data for AGS-004 were presented in a poster at the 18th Conference on Retroviruses and Opportunistic Infections (CROI) in Boston.
In the study, AGS-004 was safe and well tolerated with no additional risks observed during structured treatment interruption (STI). Argos' personalized immunotherapy resulted in an unexpectedly long delay in viral rebound, time to peak viral load during STI and a markedly reduced viral load when compared to pre-antiretroviral therapy (ART) levels. A number of patients were able to continue the STI past 12 weeks, and they were able to generate CD8+ T cell proliferative responses to the individual antigens presented in AGS-004.
"The final analysis of the Phase 2a data reiterates our findings from the previously reported interim analysis that AGS-004 is well tolerated, immunogenic, potentially efficacious and safe," said Jean-Pierre Routy, M.D., principal investigator of the study at the McGill University Health Centre in Montreal. "Further testing will demonstrate that AGS-004 is a feasible treatment option for HIV-1 infected patients."
The Phase 2a trial, AGS-004-001, was a single-arm, open-label study of the safety, antiviral activity, and immunogenicity of AGS-004 in 22 HIV-infected patients in the U.S. Subjects received four doses of AGS-004 while on ART and then interrupted antiretroviral drug treatment while receiving study drug.
"AGS-004 is currently in a Phase 2b clinical trial that will further demonstrate the immunotherapy's efficacy and safety in the treatment of HIV patients," said Jeff Abbey, president and chief executive officer of Argos. "The Phase 2b study is expected to enroll a total of 42 patients in nine sites in the U.S. and Canada, and it is funded by the National Institutes of Health as part of a $32 million contract that Argos was awarded in 2006. We are also planning to initiate a Phase 3 clinical trial with our Arcelis immunotherapy in renal cell carcinoma, AGS-003, in mid-2011."
The Phase 2a study's primary endpoint was to assess the ability of AGS-004 to improve immune control of HIV-1 replication, as measured by the proportion of subjects with HIV-1 RNA levels of <1000 copies/mL on at least three time points after STI. Secondary endpoints included the immunologic activity as measured by CD8+ T cell responses to AGS-004 therapy and HIV-1 RNA set point established after STI versus pre-ART plasma HIV-1 RNA set point.