Analytical treatment interruption in chronic HIV-1 infection: time and magnitude of viral rebound in adults with 10 years of undetectable viral load and low HIV-DNA (APACHE study).

OBJECTIVES: Despite the fact that there are individuals who have chronic HIV infection, few studies have investigated ART interruption in this setting. The aim of this study was to evaluate the ability to spontaneously control viral replication during analytical treatment interruption (ATI) in adults with chronic HIV-1 infection, on ART, with suppressed viraemia for >10 years and with a low reservoir. PATIENTS AND METHODS: This was a prospective, open-label, single-arm, non-randomized, proof-of-concept study (NCT03198325) of subjects with chronic HIV-1 infection, HIV-RNA <50 copies/mL for ≥10 years, without residual viraemia for ≥5 years, CD4+ >500 cells/mm3, HIV-DNA <100 copies/106 PBMCs and without comorbidities or AIDS-defining diseases. Enrolled patients were strictly monitored. The ART regimen in use at ATI was resumed in the case of confirmed viral rebound (CVR, two consecutive HIV-RNA >50 copies/mL). Results are reported as median (IQR). RESULTS: Nine patients underwent ATI. All participants experienced CVR [4.84 (IQR: 3.47-6.47) HIV-RNA log10 copies/mL] after ATI at a median time of 21 days (range 14-56) and restarted ART. After ART resumption, all the subjects achieved HIV-RNA <50 copies/mL in a median of 88 days (range 15-197). No serious adverse event occurred; one subject experienced acute retroviral syndrome. No significant correlation between baseline factors and time to viral rebound was observed, while the magnitude of viral rebound was significantly associated with pre-ART HIV-1 RNA (Spearman r = 0.786, P = 0.036), nadir CD4+ (Spearman r = -0.800, P = 0.010), baseline CD4+ (Spearman r = -0.667, P = 0.049) and years with undetectable viral load (Spearman r = -0.717, P = 0.030). CONCLUSIONS: Despite a long period of HIV viral load suppression and a low viral reservoir, early and consistent viral rebound was observed during ATI in all subjects.