***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Objective : To evaluate atazanavir/ritonavir ( ATV/RTV ) ( 300/100 mg ) once daily , atazanavir/saquinavir ( ATV/SQV ) ( 400/1200 mg ) once daily , and lopinavir/ritonavir ( LPV/RTV ) ( 400/100 mg ) twice daily , each with tenofovir ( 300 mg ) once daily and a nucleoside reverse transcriptase inhibitor in treatment-experienced HIV-infected patients . Methods : R and omized , open-label , 48-week multicenter trial of 358 r and omized adult patients who had failed two or more prior HAART regimens with baseline HIV RNA ≥ 1000 copies/ml and CD4 cell count ≥ 50 × 106 cells/l . Results : The primary efficacy endpoint [ plasma HIV RNA reduction assessed by time-averaged difference ( TAD ) ] was similar for ATV/RTV and LPV/RTV [ TAD 0.13 ; 97.5 % confidence interval , −0.12 to 0.39 ] at 48 weeks . Mean reductions from baseline for ATV/RTV and LPV/RTV were comparable at 1.93 and 1.87 log10 copies/ml , respectively . Mean CD4 cell count increases were 110 and 121 × 106 cells/l for ATV/RTV , and LPV/RTV , respectively . The efficacy  of ATV/SQV was lower than LPV/RTV by both these parameters . Declines in total cholesterol and fasting triglycerides were greater with ATV/RTV and ATV/SQV than with LPV/RTV ( P ≤ 0.005 ) . Lipids in the LPV/RTV arm at week 48 generally increased from baseline . Lipid-lowering agents were used more frequently in the LPV/RTV arm than in the ATV arms ( P < 0.05 versus ATV/RTV ) , as were antidiarrheal agents ( P ≤ 0.04 versus both ATV treatments ) . No new or unique safety findings emerged . Conclusions : ATV boosted with RTV is as effective and well tolerated as LPV/RTV in treatment-experienced patients , with a more favorable impact on serum lipids . Pharmacokinetically enhanced ATV provides a suitable choice for therapy of treatment-experienced HIV-infected patients BACKGROUND It is unclear whether metabolic or body composition effects differ between protease inhibitor-based regimens recommended for initial treatment of human immunodeficiency virus ( HIV ) infection . METHODS ATADAR is a phase 4 , open-label , multicenter , r and omized clinical trial . Stable antiretroviral-naive HIV-infected adults were r and omly assigned to atazanavir/ritonavir 300/100 mg or darunavir/ritonavir 800/100 mg in combination with tenofovir/emtricitabine daily . Predefined endpoints were treatment or virological failure , drug discontinuation due to adverse effects , and laboratory and body composition changes at 96 weeks . RESULTS At 96 weeks , 56 ( 62 % ) atazanavir/ritonavir and 62 ( 71 % ) darunavir/ritonavir patients remained free of treatment failure ( estimated difference 8.2 % ; 95 % confidence interval [ CI ] , -.6 to 21.6 ) and 71 ( 79 % ) atazanavir/ritonavir and 75 ( 85 % ) darunavir/ritonavir patients remained free of virological failure ( estimated difference 6.3 % ; 95 % CI , -.5 to 17.6 ) . Seven patients discontinued atazanavir/ritonavir and 5 discontinued darunavir/ritonavir due to adverse effects . Total and high-density lipoprotein cholesterol similarly increased in both arms , but there was a greater increase in triglycerides in the atazanavir/ritonavir arm . At 96 weeks , body fat ( estimated difference 2862.2 gr ; 95 % CI , 726.7 to 4997.7 ; P = .0090 ) , limb fat ( estimated difference 1403.3 gr ; 95 % CI , 388.4 to 2418.2 ; P = .0071 ) , and subcutaneous abdominal adipose tissue ( estimated difference 28.4 cm(2 ) ; 95 % CI , 1.9 to 55.0 ; P = .0362 ) increased more in the atazanavir/ritonavir arm than in darunavir/ritonavir arm . Body fat changes in the atazanavir/ritonavir arm were associated with higher insulin resistance . CONCLUSIONS We found no major differences between atazanavir/ritonavir and darunavir/ritonavir in efficacy , clinical ly relevant side effects , or plasma cholesterol fractions . However , atazanavir/ritonavir led to higher triglycerides and more total and subcutaneous fat than darunavir/ritonavir . Also , fat gains with atazanavir/ritonavir were associated with insulin resistance . Clinical Trials Registration . NCT01274780 BACKGROUND The use of either efavirenz or lopinavir-ritonavir plus two nucleoside reverse-transcriptase inhibitors ( NRTIs ) is recommended for initial therapy for patients with human immunodeficiency virus type 1 ( HIV-1 ) infection , but which of the two regimens has greater efficacy is not known . The alternative regimen of lopinavir-ritonavir plus efavirenz may prevent toxic effects associated with NRTIs . METHODS In an open-label study , we compared three regimens for initial therapy : efavirenz plus two NRTIs ( efavirenz group ) , lopinavir-ritonavir plus two NRTIs ( lopinavir-ritonavir group ) , and lopinavir-ritonavir plus efavirenz ( NRTI-sparing group ) . We r and omly assigned 757 patients with a median CD4 count of 191 cells per cubic millimeter and a median HIV-1 RNA level of 4.8 log10 copies per milliliter to the three groups . RESULTS At a median follow-up of 112 weeks , the time to virologic failure was longer in the efavirenz group than in the lopinavir-ritonavir group ( P=0.006 ) but was not significantly different in the NRTI-sparing group from the time in either of the other two groups . At week 96 , the proportion of patients with fewer than 50 copies of plasma HIV-1 RNA per milliliter was 89 % in the efavirenz group , 77 % in the lopinavir-ritonavir group , and 83 % in the NRTI-sparing group ( P=0.003 for the comparison between the efavirenz group and the lopinavir-ritonavir group ) . The groups did not differ significantly in the time to discontinuation because of toxic effects . At virologic failure , antiretroviral resistance mutations were more frequent in the NRTI-sparing group than in the other two groups . CONCLUSIONS Virologic failure was less likely in the efavirenz group than in the lopinavir-ritonavir group . The virologic efficacy of the NRTI-sparing regimen was similar to that of the efavirenz regimen but was more likely to be associated with drug resistance . ( Clinical Trials.gov number , NCT00050895 [ Clinical Trials.gov ] . ) BACKGROUND We assessed a once-daily combination to simplify therapy in patients infected with human immunodeficiency virus type 1 ( HIV-1 ) . METHODS A total of 355 adults with plasma HIV-1 RNA levels < 400 copies/mL were r and omly assigned to either switch to once-daily emtricitabine , didanosine , and efavirenz ( n=178 ) or maintain their protease inhibitor (PI)-based regimens ( n=177 ) . The primary end point was sustained suppression of plasma HIV-1 RNA levels to < 400 copies/mL. RESULTS At week 48 , the proportion of patients meeting the end point was 87.6 % in the PI group and 90.5 % in the once-daily group , with a treatment difference of -2.9 % ( upper bound of the 1-tailed 95 % confidence interval , 2.6 % ) . The proportion of patients with HIV-1 RNA levels < 50 copies/mL was higher in the once-daily group ( 87 % ) than in the PI group ( 79 % ) ( P<.05 ) . Resistance mutations to efavirenz and emtricitabine were detected in all patients in the once-daily group who experienced virologic failure while receiving study medication . The proportion of patients discontinuing study medication because of adverse events was similar between the once-daily group ( 9 % ) and the PI group ( 10 % ) ( P=.8 ) . CONCLUSIONS Substituting a convenient once-daily combination of emtricitabine , didanosine , and efavirenz for a PI-based regimen was well tolerated and associated with sustained virologic suppression Background : In BMS Study 045 , once-daily ( QD ) atazanavir/ritonavir ( ATV/RTV ) demonstrated comparable efficacy and safety to twice-daily ( BID ) lopinavir/ritonavir ( LPV/RTV ) over 48 weeks in treatment-experienced patients . Results of extended follow-up to 96 weeks are presented . Methods : BMS Study 045 was an open-label , r and omized , multi-national trial of HIV-infected patients with virologic failure on two or more prior HAART regimens design ed to evaluate the efficacy and safety of ATV/RTV ( 300/100 mg ) QD and LPV/RTV ( 400/100 mg ) BID , each with tenofovir ( 300 mg ) QD and one nucleoside reverse transcriptase inhibitor . The primary efficacy measure was the time-averaged difference ( TAD ) in reduction in HIV RNA from baseline . Secondary objectives included evaluation of safety and plasma lipid levels through week 96 . Results : Over 96 weeks , the ATV/RTV regimen demonstrated similar virologic efficacy to the LPV/RTV regimen . Mean reductions from baseline in HIV RNA were −2.29 and −2.08 log10 copies/ml , respectively [ TAD ( 97.5 % confidence interval ) : 0.14 log10 copies/ml ( −0.13 , 0.41 ) ] . The LPV/RTV regimen result ed in significant increases in total cholesterol ( + 9 % ) and fasting triglycerides ( + 30 % ) in comparison with the ATV/RTV regimen , which demonstrated decreases in these parameters [ −7 and −2 % , respectively , ( P < 0.0001 ) ] . Grade 2–4 diarrhoea occurred less frequently in ATV/RTV patients ( 3 % ) in comparison with LPV/RTV patients ( 13 % ) ( P < 0.01 ) . Grade 3–4 elevations in bilirubin were more common in ATV/RTV patients ( 53 % ) than LPV/RTV patients ( < 1 % ) ( P < 0.0001 ) , with no result ing discontinuations . Conclusions : Regimens containing once-daily ATV/RTV demonstrated comparable efficacy and safety , with significant reductions in total cholesterol and fasting triglycerides and improved gastrointestinal-tolerability in comparison with twice-daily regimens containing LPV/RTV over 96 weeks in treatment-experienced patients BACKGROUND Atazanavir/ritonavir is as effective as lopinavir/ritonavir , with a more favourable lipid profile and less gastrointestinal toxicity , in treatment-experienced HIV-1-infected patients . We compared these two combinations directly in treatment-naive patients . METHODS In this open-label , international non-inferiority study , 883 antiretroviral-naive , HIV-1-infected patients were r and omly assigned to receive atazanavir/ritonavir 300/100 mg once daily ( n=440 ) or lopinavir/ritonavir 400/100 mg twice daily ( n=443 ) , in combination with fixed-dose tenofovir/emtricitabine 300/200 mg once daily . R and omisation was done with a computer-generated central ised r and omisation schedule and was stratified by baseline levels of HIV RNA ( viral load ) and geographic region . The primary endpoint was the proportion of patients with viral load less than 50 copies per mL at week 48 . The main efficacy analysis was done by intention to treat . This trial is registered with Clinical Trials.gov , number NCT00272779 . FINDINGS At week 48 , 343 ( 78 % ) of 440 patients receiving atazanavir/ritonavir and 338 ( 76 % ) of 443 patients receiving lopinav 
    Output:
    
The pooled effect estimate did not favor ATZ/r over DRV/r regarding the change in plasma levels of total cholesterol , triglycerides , or high-density lipoprotein at 24 , 48 , and 96 weeks .
The ATZ/r regimen was generally as effective and well-tolerated as the LPV/r regimen for the treatment of HIV-1 patients .
Compared to the DRV/r regimen , ATZ/r has no favorable effect on the plasma lipid profile or adipose tissue distribution