Background: once-daily combinations of efavirenz and two nucleoside analogues are recommended for the treatment of HIV infection. Long-term efficacy and safety data are scarce for the combination of efavirenz, emtricitabine and didanosine.
Methods: the ALIZE ANRS 099 trial enrolled 355 adults with plasma HIV RNA levels of <400 copies/mL under a protease inhibitor-based regimen, who were randomized to remain on this regimen or to switch to a once-daily regimen of emtricitabine, didanosine and efavirenz for 48 weeks. An extended 4 year follow-up was available for the 178 patients who switched to the efavirenz-containing regimen, and assessed plasma HIV RNA levels, CD4 cell counts, safety and tolerability.
Results: after a median follow-up of 42 months, 121 patients (68%) remained on an efavirenz-based regimen, and 62% and 57% had plasma HIV RNA levels of <400 and <50 copies/mL, respectively, in an intent-to-continue analysis with missing data and treatment discontinuation considered as failure. There was a significant increase in CD4 cell count of 41 cells/mm(3). Drug-related adverse events were the main reason for treatment discontinuation in 26 patients (15%), and 15 were reported during the first year of therapy (58%). There was no emergence of clinically defined lipodystrophy, and lipid and glucose profiles were favourable with a significant increase from baseline of high-density lipoprotein cholesterol levels (median increase 12 mg/dL, P < 10(-4)).
Conclusions: a once-daily regimen of emtricitabine, didanosine and efavirenz provided a durable antiretroviral response and was well tolerated through 4 years of therapy.