Development of HIV with drug resistance after CD4 cell count-guided structured treatment interruptions in patients treated with highly active antiretroviral therapy after dual-nucleoside analogue treatment. SENC (Spanish efavirenz vs. nevirapine comparison) trial: a randomized, open-label study in HIV-infected naive individuals. Triple-nucleoside regimens versus efavirenz-containing regimens for the initial treatment of HIV-1 infection. Virologic, immunologic, clinical, safety, and resistance outcomes from a long-term comparison of efavirenz-based versus nevirapine-based antiretroviral regimens as initial therapy in HIV-1-infected persons.
For patients with human immunodeficiency virus (HIV) infection, structured treatment interruption (STI) is an attractive alternative strategy to continuous treatment, particularly in resource-restrained settings, because it reduces both side effects and costs. One major concern, however, is the development of resistance to antiretroviral drugs that can occur during multiple cycles of starting and stopping therapy.
                HIV genotypic drug resistance was investigated in 20 HIV-infected Thai patients treated with highly active antiretroviral therapy (HAART) and CD4 cell count-guided STI after dual nucleoside reverse-transcriptase inhibitor (NRTI) treatment. Resistance was tested at the time of the switch from dual-NRTI treatment to HAART and when HAART was stopped during the last interruption.
                After STI, one major drug-resistance mutation occurred (T215Y), and, in the 4 samples with preexisting major mutations (D67N [n=2], K70R [n=2], T215Y [n=2], and T215I [n=1]), the mutations disappeared. All mutations in the HIV protease gene were minor mutations already present, in most cases, before STI was started, and their frequency was not increased through STI, whereas the frequency of reverse-transcriptase gene mutations significantly decreased after the interruptions. After the 48-week study period, no patients had virological failure. Long-term follow-up (108 weeks) showed 1 case of virological failure in the STI arm and 1 in the continuous arm. No virological failure was seen in patients with major mutations.
                Major HIV drug-resistance mutations were not induced through CD4 cell count-guided treatment interruptions in HIV-infected patients successfully treated with HAART after dual-NRTI therapy. A randomized, open-label, pilot study was undertaken to explore the antiviral activity and tolerability of two nonnucleoside reverse transcriptase inhibitors (NNRTIs), nevirapine (NVP) and efavirenz (EFV).
                HIV-infected antiretroviral-naive adults with CD4 counts >100 cells/mm(3) and detectable plasma HIV RNA below 100,000 copies/mL were randomized to receive didanosine (ddI) and stavudine (d4T) plus either NVP or EFV. Assessments were made every 12 weeks. Primary endpoints were the proportion of patients reaching plasma HIV RNA <50 copies/mL and/or developing NNRTI-related toxicities leading to drug discontinuation. Baseline characteristics were comparable for participants in the EFV (n = 31) and NVP arms (n = 36).
                At 48 weeks, 23/31 (74%) patients in the EFV group and 23/36 (64%) in the NVP group had <50 HIV RNA copies/mL (intention-to-treat analysis). Adverse events led to NNRTI discontinuation in 4 and 3 patients in the EFV and NVP arms, respectively. There were no statistically significant differences between groups regarding any primary endpoint. NVP and EFV along with two NRTIs may be equally well tolerated and effective at achieving <50 HIV RNA copies/mL in naive patients with CD4 counts >100 cells/mm(3) and HIV RNA <10(5) copies/mL.
                A much larger study is needed to demonstrate any significant differences between NVP and EFV, if they exist at all. Regimens containing three nucleoside reverse-transcriptase inhibitors offer an alternative to regimens containing nonnucleoside reverse-transcriptase inhibitors or protease inhibitors for the initial treatment of human immunodeficiency virus type 1 (HIV-1) infection, but data from direct comparisons are limited.
                This randomized, double-blind study involved three antiretroviral regimens for the initial treatment of subjects infected with HIV-1: zidovudine-lamivudine-abacavir, zidovudine-lamivudine plus efavirenz, and zidovudine-lamivudine-abacavir plus efavirenz.
                We enrolled a total of 1147 subjects with a mean baseline HIV-1 RNA level of 4.85 log10 (71,434) copies per milliliter and a mean CD4 cell count of 238 per cubic millimeter were enrolled. A scheduled review by the data and safety monitoring board with the use of prespecified stopping boundaries led to a recommendation to stop the triple-nucleoside group and to present the results in the triple-nucleoside group in comparison with pooled data from the efavirenz groups. After a median follow-up of 32 weeks, 82 of 382 subjects in the triple-nucleoside group (21 percent) and 85 of 765 of those in the combined efavirenz groups (11 percent) had virologic failure; the time to virologic failure was significantly shorter in the triple-nucleoside group (P<0.001). This difference was observed regardless of the pretreatment HIV-1 RNA stratum (at least 100,000 copies per milliliter or below this level; P< or =0.001 for both comparisons). Changes in the CD4 cell count and the incidence of grade 3 or grade 4 adverse events did not differ significantly between the groups.
                In this trial of the initial treatment of HIV-1 infection, the triple-nucleoside combination of abacavir, zidovudine, and lamivudine was virologically inferior to a regimen containing efavirenz and two or three nucleosides.
                Copyright 2004 Massachusetts Medical Society To compare long-term virologic, immunologic, and clinical outcomes in antiretroviral-naïve persons starting efavirenz (EFV)- versus nevirapine (NVP)-based regimens.
                The FIRST study randomized patients into three strategy arms: PI+NRTI, NNRTI+NRTI, and PI+NNRTI+NRTI. NNRTI was determined by optional randomization (NVP or EFV) or by choice. For this randomized substudy, the primary endpoint was HIV RNA >50 copies/mL after 8 months or death. Genotypic resistance testing was done at virologic failure (VF; HIV RNA >1,000 copies/mL at or after 4 months).
                228 persons (111 randomized to EFV, 117 to NVP) were followed for median 5 years. Rates per 100 person years for the primary endpoint were 41.2 (EFV) and 42.8 (NVP; p = .59). The percent of persons with HIV RNA <50 copies/mL was similar throughout follow-up (p = .24), as were average increases in CD4+ cells (p = .30). 423 persons declining the substudy chose EFV; 264 chose NVP. There were 915 persons in the combined cohort (randomized and choice). In the combined cohort, the risk of VF and VF with any NNRTI or NRTI resistance or resistance of any class was significantly less for EFV compared to NVP.
                EFV-based regimens as initial therapy resulted in a lower risk of VF and VF with resistance than did NVP-based regimens, although immunologic and clinical outcomes were similar.
Both drugs have equivalent efficacies in initial treatment of HIV infection when combined with two NRTIs, but different side effects.