Once virological failure is confirmed and a resistance result available, the regimen is changed as soon as possible to avoid accumulation of resistance mutations. The choice of the new ART regimen will primarily depend on the results of resistance testing and the patient’s preference. Additional considerations include the results of tropism and HLA-B*57 testing, DDIs/food interactions, co-morbidities and future therapy options. The goal of the new combination

is to re-establish a VL <50 copies/mL. In PLX3397 patients with ongoing viraemia and with few options to construct a fully suppressive regimen, referral for specialist advice and/or discussion in a multidisciplinary team ‘virtual’ clinic. Include at least two and preferably three fully active agents with at least one active PI/r (e.g. DRV/r) and one agent with a novel mechanism of action (CCR5 antagonist/integrase or fusion selleck kinase inhibitor inhibitor). Treatment interruption is not recommended. No resistance (WT virus). 3TC/FTC resistance (M184V/I) following any first-line therapy, including TDF/FTC or ABC/3TC. NNRTI resistance (e.g. K103N or Y181C/I/V) and/or 3TC/FTC resistance (following first-line therapy with NNRTI-based regimen, including TDF/FTC or ABC/3TC). INI resistance (e.g. Q148 or N155H) and/or 3TC/FTC

resistance (following first-line therapy with RAL-based regimen, including TDF/FTC or ABC/3TC). Extended RT resistance (e.g. K65R/L74V or thymidine analogue mutations) (following suboptimal regimens/patients with more extensive drug history associated with virological failure). Three-class resistance (indicating NRTI, NNRTI and PI) (following multiple failing regimens). Limited or no therapeutic options (following multiple failing regimens, including the newer drugs with novel actions). Record in patient’s notes of resistance result at ART initiation (if available) and at first VL >400 copies/mL and/or before switch. Record in patient’s oxyclozanide notes of adherence assessment and tolerability/toxicity to ART in patients experiencing virological failure or repeated

viral blips. Number of patients experiencing virological failure on current ART regimen. Proportion of patients experiencing virological failure switched to a new suppressive regimen within 6 months. Proportion of patients on ART with previously documented HIV drug resistance with VL <50 copies/mL. Record of patients with three-class virological failure with or without three-class resistance referred/discussed in multidisciplinary team with expert advice. In patients on ART: A single VL 50–400 copies/mL preceded and followed by an undetectable VL is usually not a cause for clinical concern (GPP). We recommend a single VL >400 copies/mL is investigated further, as it is indicative of virological failure (1C). We recommend in the context of repeated viral blips, resistance testing is attempted (1D). Optimal HIV control is ordinarily reflected by complete viral suppression with an undetectable VL.