Pegylated Interferon Alfa-2a Monotherapy Results in Suppression of HIV Type 1 Replication and Decreased Cell-Associated HIV DNA Integration

Background. Antiretroviral therapy (ART)-mediated immune reconstitution fails to restore the capacity of the immune system to spontaneously control human immunodeficiency virus (HIV) replication. Methods. A total of 23 HIV type 1 (HIV-1)-infected, virologically suppressed subjects receiving ART (CD4(+) T-cell count, >450 cells/mu L) were randomly assigned to have 180 mu g/week (for arm A) or 90 mu g/week (for arm B) of pegylated (Peg) interferon alfa-2a added to their current ART regimen. After 5 weeks, ART was interrupted, and Peg-interferon alfa-2a was continued for up to 12 weeks (the primary end point), with an option to continue to 24 weeks. End points included virologic failure (viral load, >= 400 copies/mL) and adverse events. Residual viral load and HIV-1 DNA integration were also assessed. Results. At week 12 of Peg-interferon alfa-2a monotherapy, viral suppression was observed in 9 of 20 subjects (45%), a significantly greater proportion than expected (arm A, P = .0088; arm B, P = .0010; combined arms, P < .0001). Over 24 weeks, both arms had lower proportions of subjects who had viral load, compared with the proportion of subjects in a historical control group (arm A, P = .0046; arm B, P = .0011). Subjects who had a sustained viral load of < 400 copies/mL had decreased levels of integrated HIV DNA (P = .0313) but increased residual viral loads (P = .0078), compared with subjects who experienced end-point failure. Conclusions. Peg-interferon alfa-2a immunotherapy resulted in control of HIV replication and decreased HIV-1 integration, supporting a role for immunomediated approaches in HIV suppression and/or eradication.