Delayed progression to AIDS in volunteers treated with long-term HIV-1 Immunogen (REMUNE®) therapy in Thailand

Objectives. To observe the long-term effects of an immune-based therapy HIV-1 Immunogen (REMUNE®; Immune Response Corp., Carlsbad, CA, USA) as a first course of treatment designed to sustain the immune system and thus delay the initiation of therapy with antiretroviral drugs and/or delay disease progression. Methods. In this open-label, multi-institute extended phase II P2101B study, disease progression, CD4 and CD8 T-cell counts, HIV-1 RNA levels, and genotypic antiretroviral drug resistance were examined in 223 asymptomatic HIV-1-infected Thai volunteers receiving REMUNE® every 12 weeks over 132 weeks. A subset of subjects was randomly selected by the physicians to receive antiretroviral drugs for 10 months. Results. Patients treated with REMUNE® demonstrated a low rate of clinical disease progression (0.72 per 100 person-years), higher CD4 and CD8 T-cell counts, higher body weight before and after treatment in the same patient, and stable viral load with no serious adverse events. We found no genotypic evidence of drug resistance in subgroups of patients on REMUNE® monotherapy or REMUNE® plus antiretrovirals (ARTs). Conclusions. This Thai study, like previous US and European studies, confirms that therapeutic immunization of HIV-infected volunteers modifies disease progression, as evidenced by stabilization of CD4 and CD8 T-cell counts, body weight, and viral load. As the majority of asymptomatic patients demonstrated an objective response to immunization, this study suggests that REMUNE® may be utilized prior to initiation of antiviral drug therapy when CD4 cell counts are still above the current ART guidelines. Further work should be carried out to examine its potential use in combination with ART in order to reduce the increasingly common occurrence of drug resistance.