Efavirenz Arm Research Articles

Long-Term Body Fat Outcomes in Antiretroviral-Naive Participants Randomized to Nelfinavir or Efavirenz or Both Plus Dual Nucleosides

Long-term regional body fat outcomes have not been well described in randomized antiretroviral drug trials. Dual x-ray absorptiometry (DXA) scans were performed every 16 weeks on a subset of 157 antiretroviral-naive participants who were randomized to receive nelfinavir, efavirenz, or both, combined with zidovudine and lamivudine or stavudine and didanosine, in a multicenter trial. Participants with any available data after baseline up to week 144 contributed to this as-treated analysis. Limb fat increased similarly in all groups during the first 32 weeks. After week 32, limb fat changed by - 1.7% per year for zidovudine-lamivudine and by -19.0% per year for didanosine-stavudine (mixed model analysis of variance [MMANOVA], P < 0.0001). Adjusting for nucleoside backbone, there was an additional decrease in limb fat of -8.7% per year for the combined nelfinavir and nelfinavir + efavirenz group compared with the efavirenz group (MMANOVA, P = 0.03). Among participants receiving zidovudine-lamivudine, after week 32, limb fat changed by +2.7% per year with efavirenz and by -7.9% per year for the combined nelfinavir and nelfinavir + efavirenz group (MMANOVA, P = 0.03). Over 144 weeks, zidovudine-lamivudine was superior to didanosine-stavudine with regard to limb fat loss. The combination of zidovudine, lamivudine, and efavirenz showed no overall pattern suggesting limb fat loss over time and was significantly superior to the pooled zidovudine-lamivudine-nelfinavir (with and without efavirenz) arms.

Snapshots for July 2007

Snapshots for July 2007

Metabolic Effects of Protease Inhibitor-Sparing Antiretroviral Regimens Given as Initial Treatment of HIV-1 Infection (AIDS Clinical Trials Group Study A5095)

To assess metabolic changes after initiation of protease inhibitor (PI)-sparing regimens in antiretroviral-naive patients. Metabolic changes were analyzed within the triple-nucleoside (zidovudine [ZDV]/lamivudine [3TC]/abacavir [ABC])-containing, 3-drug efavirenz (EFV) [ZDV/3TC + EFV]-containing, and 4-drug EFV [ZDV/3TC/ABC + EFV]-containing arms of the AIDS Clinical Trials Group multicenter trial A5095. Metabolic values were compared with published US general population norms. From week 0 to week 24, all arms exhibited similar mild median increases in glucose and decreases in insulin sensitivity, whereas changes in lipids were greater in the ZDV/3TC + EFV and ZDV/3TC/ABC + EFV arms than in the ZDV/3TC/ABC arm: triglyceride (TG; 7, 18, and -1 mg/dL, respectively), total cholesterol (TC; 23, 28, and 5 mg/dL, respectively), low-density lipoprotein cholesterol (LDL-C; 9, 14, and 1 mg/dL, respectively), and high-density lipoprotein cholesterol (HDL-C; 10, 10, and 5 mg/dL, respectively). Adjusted mean study lipid values of all study participants at week 0 and week 96 compared with those of the National Health and Nutrition Examination Survey (NHANES) 1999 through 2002 values were: TG (148, 187, and 123 mg/dL, respectively), TC (164, 195, and 203 mg/dL, respectively), HDL-C (35, 47, and 51 mg/dL, respectively), and LDL-C (101, 117, and 123 mg/dL, respectively) (P < or = 0.005 for each value vs. NHANES values). Similar mild increases in glucose and decreases in insulin sensitivity were observed in all regimens, whereas lipids were modestly higher in the EFV-containing arms. Compared with general population norms, the metabolic dysfunctions of concern after these PI-sparing therapies were increasingly abnormal TC and lower (but improved relative to baseline) HDL-C levels.

British HIV Association (BHIVA) guidelines for the treatment of HIV‐infected adults with antiretroviral therapy (2006)

British HIV Association (BHIVA) guidelines for the treatment of HIV‐infected adults with antiretroviral therapy (2006)

Early Virologic Nonresponse to Tenofovir, Abacavir, and Lamivudine in HIV‐Infected Antiretroviral‐Naive Subjects

Antiretroviral combinations that reduce the number of pills and dosing frequency have the potential to simplify therapy. We compared 2 regimens dosed as 2 pills once daily. This was a randomized, open-label, multicenter study of tenofovir disoproxil fumarate versus efavirenz, both administered once daily with the abacavir/lamivudine fixed-dose combination in treatment-naive human immunodeficiency virus type 1 (HIV-1)-infected subjects. After reports of early nonresponse, an unplanned interim analysis was performed. Virologic nonresponse was defined as (1) a <2.0-log(10) copies/mL decrease in HIV-1 RNA level by week 8, (2) an HIV-1 RNA rebound of > or =1.0 log(10) copies/mL above the nadir, or (3) for subjects with 2 consecutive HIV-1 RNA measurements <50 copies/mL, a subsequent increase to >400 copies/mL on 2 consecutive occasions. We randomized 340 subjects. Median baseline HIV-1 RNA level and CD4+ cell count were 4.7 log(10) copies/mL and 251 cells/mm3, respectively; 194 subjects with HIV-1 RNA data from > or =8 weeks were included in the interim analysis. Virologic nonresponse occurred in 50 (49%) of 102 subjects in the tenofovir disoproxil fumarate arm, compared with 5 (5%) of 92 of subjects in the efavirenz arm (P<.001). Within 12 weeks, viral genotypes for nonresponders in the tenofovir disoproxil fumarate arm showed M184V or I/M/V mixtures in 40 (98%) of 41 subjects and K65R and M184V or mixtures in 22 (54%) of 41 subjects. The protocol was immediately amended to modify the tenofovir disoproxil fumarate arm. The efavirenz arm continued unchanged; after 48 weeks, 120 (71%) of 169 subjects achieved HIV-1 RNA levels <50 copies/mL. The tenofovir disoproxil fumarate/abacavir/lamivudine regimen resulted in an unexpected and unacceptably high rate of nonresponse and incidence of K65R and M184V/I. This 3-drug regimen should not be used.

Genotypic and phenotypic resistance patterns at virological failure in a simplification trial with nevirapine, efavirenz or abacavir

The NEFA Study was a randomized study comparing nevirapine (NVP), efavirenz (EFV) or abacavir (ABC) as substitutes for protease inhibitors in a large group of HIV-1-infected patients successfully treated with antiretroviral regimens containing protease inhibitors. To evaluate genotype and phenotype resistance patterns among patients who have experienced virological failure under one of the three study arms. Patients with virological failure, defined as two consecutive determinations of HIV-1 RNA > 200 copies/ml, were analysed for phenotypic susceptibility and HIV-1 mutations. Of the 460 patients included in the study, 51 (11%) experienced virological failure after 24 months of follow-up while on assigned study medication. A higher proportion of patients in the ABC [25 (17%)] than in the NVP [14 (9%)] or EFV [12 (8%)] arms selected resistance to the study drug (P = 0.04). Moreover, a much higher number of resistance mutations to one or more of the backbone nucleoside reverse transcriptase inhibitor drugs contained in the failing regimen were observed in the ABC than in the EFV or NVP arms. In general, there was a good concordance among genotype and phenotype resistance testing, except for ABC, stavudine and didanosine, where phenotypic resistance testing added valuable information (fold change in the median inhibitory concentration). Cross-resistance involving nucleoside reverse transcriptase inhibitor drugs might explain the higher risk of virological failure in patients switched to ABC-containing antiretroviral therapy. Phenotypic resistance testing may be helpful in interpreting unclear genotypic results.

Metabolic benefits 24 months after replacing a protease inhibitor with abacavir, efavirenz or nevirapine

To evaluate the 24-month metabolic and morphological benefits obtained from replacing the protease inhibitor (PI) in a regimen with nevirapine, efavirenz or abacavir. NEFA was a randomized study designed to compare the efficacy of nevirapine, efavirenz or abacavir as substitutes for PI. A subset of 90 patients [abacavir (n = 29), efavirenz (n = 32), nevirapine (n = 29)] formed the metabolic study. Fasting total cholesterol (TC), high density lipoprotein cholesterol (HDL-c) and triglycerides levels were determined. Glucose homeostasis parameters were also collected. Lipodystrophy was evaluated by clinical examination and morphological measurements. Treatment simplification led to overall lipid profile improvements. At 24 months, the two non-nucleoside reverse transcriptase inhibitors produced similar lipid benefits: HDL-c levels increased [efavirenz, 15% (P = 0.001); nevirapine, 21% (P < 0.001)] and TC to HDL-c ratios decreased [efavirenz, 14% (P < 0.001); nevirapine, 19% (P < 0.01)], an effect not observed in the abacavir arm. Non-HDL-c levels decreased by 10% in both the abacavir (P = 0.001) and efavirenz (P < 0.05) arms. Significant decreases in the levels of triglycerides occurred for the first year in all treatments; however, at 24 months most of the initial loss had been regained. Patients with baseline moderate or severe lipodystrophy obtained less-pronounced lipid benefits. Several insulin resistance markers showed a trend towards improvement. Conversely, no improvements in morphological abnormalities were observed. Replacing PI with efavirenz, nevirapine or abacavir improved the lipid profile, with more marked results in non-lipodystrophic patients. In contrast, this strategy does not seem to be effective for reversing body fat abnormalities.

Early Virological Failure after Tenofovir + Didanosine + Efavirenz Combination in HIV-Positive Patients upon Starting Antiretroviral Therapy

A prospective, randomized pilot trial was conducted in naive patients comparing three different combinations: zidovudine+lamivudine+lopinavir/ritonavir (arm A) versus tenofovir+lamivudine+efavirenz (arm B) versus tenofovir+didanosine+efavirenz (arm C). HIV-RNA slope (days 1, 3, 7, 14 and 28) was slower in arm C with respect to arm B (P < 0.0001). Seven out of eight patients (87.5%) reached undetectable HIV-RNA by week 28 in arm A, 10/10 (100%) in arm B and 6/10 (60%) in arm C. Among arm C patients who failed at week 4, one HIV isolate showed 67N and 219Q, and another one showed 210F and 215D substitutions in the HIV reverse transcriptase gene at baseline, respectively. Non-nucleoside reverse transcriptase inhibitor resistance-related mutations appeared first, followed by 65R mutations in all cases. Efavirenz AUC(0-24) values were lower in arm C with respect to arm B, especially in patients who failed early. A high virological failure rate after tenofovir+didanosine+efavirenz correlated with a slower HIV-RNA decrease and a peculiar accumulation of resistance mutations. A constellation of factors could be correlated with early failure events in patients receiving this combination such as resistance mutations or polymorphisms present at baseline, low CD4+ T-cell count or advanced disease and unexpectedly low efavirenz plasma levels.

Mutations and polymorphisms associated with antiretroviral drugs in HIV-1C-infected African patients.

To detect and characterize polymerase gene (pol) polymorphisms and mutation patterns in HIV-1C-infected Batswana patients treated with reverse transcriptase inhibitors, samples from AIDS patients treated with highly active antiretroviral therapy (HAART) were sequenced for the region encompassing the entire HIV-1 protease (PR) and the first 335 amino acids of reverse transcriptase (RT). Amongst the 16 patients treated with antiretroviral (ARV) drugs, eight started HAART regimens containing didanosine, stavudine and nevirapine (ddI/d4T/NVP) or efavirenz (EFV) (arm A) while the others started with zidovudine (AZT) and lamivudine (3TC) given together as combivir (CBV) with either NVP or EFV as arm B. Arm B is the first line regimen currently provided by the Botswana ARV national programme. Greater efficacy, in terms of treatment duration, was observed in patients in arm B (14 months) as compared with patients in arm A (9 months); P<0.05, n=8. Appearance of the M184V mutation in the arm B patients coincided with a rebound of viral load (VL) (4.3 +/-0.1 log10 RNA copies/ml) and a significantly improved immunological parameter (deltaCD4=207.0+/-48.1 cells/microl; P<0.05). Interestingly, patients developing the M184V mutation preferentially harboured polymorphisms Q174K and/or I178L located in close proximity to pol position 184. The M184V mutation occurred following a clear clinical benefit consisting of increased CD4 cell counts and lower plasma viral loads. Primary mutations known to be associated with NNRTI and NRTI resistance for HIV-1B were observed in 10 of the 16 treated patients.

New antiretroviral drugs and approaches to HIV treatment.

New antiretroviral drugs and approaches to HIV treatment.

SENC (Spanish efavirenz vs. nevirapine comparison) trial: A randomized, open-label study in HIV-infected naive individuals

PURPOSE: 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). METHOD: HIV-infected antiretroviral-naive adults with CD4 counts >100 cells/mm3 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). RESULTS: 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/mm3 and HIV RNA <105 copies/mL. CONCLUSION: A much larger study is needed to demonstrate any significant differences between NVP and EFV, if they exist at all.

SENC (Spanish efavirenz vs. nevirapine comparison) trial: A randomized, open-label study in HIV-infected naive individuals

PURPOSE: 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). METHOD: HIV-infected antiretroviral-naive adults with CD4 counts >100 cells/mm3 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). RESULTS: 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/mm3 and HIV RNA <105 copies/mL. CONCLUSION: A much larger study is needed to demonstrate any significant differences between NVP and EFV, if they exist at all.