This study is a placebo-controlled study aimed at assessing the safety of ABX464 administered at 50 mg o.d. and 150 mg versus placebo in HIV infected patients who are treated with darunavir + ritonavir (DRV/RTV) or darunavir + cobicistat (DRV/COBI). Eligible patients should be treated with darunavir + ritonavir or darunavir + cobicistat as monotherapy for at least 8 weeks prior to baseline. Patients should be fully suppressed (< 50 copies/mL) at least during the last 6 months prior to enrolment.