• Proportion of patients with plasma HIV-1 RNA <50 copies/mL at W24 [ Time Frame: week 24 ] [ Designated as safety issue: No ]
  

• Time to loss of virological response (TLOVR analysis; FDA algorithm) at W12, W24 and W48 (<50 copies/mL) [ Time Frame: week 12, 24, and 48 ] [ Designated as safety issue: No ]
  
• Proportion of patients with plasma HIV-1 RNA <50 copies/mL at W48 [ Time Frame: week 48 ] [ Designated as safety issue: No ]
  

ATC has potent antiviral activity both in vitro (against wild-type HIV-1 and HIV-1 with mutations in reverse transcriptase that confer resistance to NRTIs), and in clinical studies in both treatment-naïve and treatment-experienced patients with M184V, including in the presence of additional NRTI mutations in reverse transcriptase.

The M184V mutation is most commonly present amongst patients failing regimens containing either of the two deoxycytidine analogs lamivudine and emtricitabine. Whilst lamivudine therapy is often maintained in patients harboring the M184V mutation in some settings, there are no deoxycytidine analogs currently available that effectively suppress replication of HIV-1 containing the M184V/I mutation, particularly in the presence of other additional NRTI mutations.

The purpose of this study is to extend the efficacy and safety established in study AVX-201 of ATC in patients who are HIV-1 infected and have failed treatment with lamivudine or emtricitabine and have confirmed M184V/I mutation. Patients to be enrolled will be failing their current lamivudine- or emtricitabine-containing regimen and therefore have limited remaining NRTI treatment options. This study will investigate whether it is possible to improve control of HIV-1 viral replication by including ATC within a treatment experienced patient's new optimized background regimen following ART treatment failure.