[show abstract][hide abstract] ABSTRACT: As antiretroviral regimens for the treatment of HIV infection improve, trials providing data on long-term follow-up are increasingly important.
A regimen of tenofovir disoproxil fumarate (TDF), emtricitabine (FTC), and efavirenz (EFV) demonstrated superior virologic, immunologic and morphologic effects compared with a regimen of fixed-dose zidovudine/lamivudine (ZDV/3TC) and EFV through 96 weeks in a randomized open-label trial. After 96 weeks, patients on TDF + FTC transitioned to fixed-dose combination TDF/FTC.
Through 144 weeks, significantly more patients in the TDF/FTC arm reached and maintained an HIV RNA level <400 copies/mL (71% receiving TDF/FTC and EFV vs. 58% receiving ZDV/3TC and EFV; P = 0.004), with a trend toward greater CD4 cell increase in the TDF/FTC arm (312 vs. 271 cells/mm; P = 0.09). Over 144 weeks of follow-up, more patients in the ZDV/3TC arm discontinued therapy because of adverse events (11% vs. 5%; P = 0.01) and no patients discontinued because of renal events. Patients in the ZDV/3TC arm had significantly less limb fat than patients in the TDF/FTC arm (5.4 vs. 7.9 kg; P < 0.001) at 144 weeks.
Cumulative results from 3 years of follow-up suggest that a regimen of TDF/FTC and EFV demonstrates superior durability of viral load suppression and an improved safety and morphologic profile compared with ZDV/3TC and EFV.
[show abstract][hide abstract] ABSTRACT: In antiretroviral-naive patients, tenofovir disoproxil fumarate (TDF), emtricitabine (FTC), and efavirenz (EFV) demonstrated superior outcomes compared with fixed-dose zidovudine (ZDV)/lamivudine (3TC) and EFV through 48 weeks. Results through a 96-week extension phase are presented.
In this randomized, open-label, noninferiority trial, 517 antiretroviral-naive HIV-infected patients received TDF, FTC, and EFV (TDF + FTC + EFV) or ZDV/3TC and EFV (ZDV/3TC + EFV). The primary endpoint was the proportion of patients with an HIV RNA level <400 copies/mL in patients without baseline nonnucleoside resistance.
Through week 96, significantly more patients receiving TDF + FTC + EFV achieved and maintained an HIV RNA level <400 copies/mL (75% receiving TDF + FTC + EFV vs. 62% receiving ZDV/3TC + EFV; P = 0.004). There was a trend toward greater virologic suppression to <50 copies/mL in the TDF + FTC + EFV group (67% vs. 61%; P = 0.16). The TDF + FTC + EFV group demonstrated a significantly greater increase in CD4 count (270 vs. 237 cells/mm; P = 0.036). No patient developed the K65R mutation. Limb fat at week 96 was significantly greater in the TDF + FTC + EFV group versus the ZDV/3TC + EFV group (7.7 vs. 5.5 kg; P < 0.001).
Over 96 weeks, the combination of TDF, FTC, and EFV was superior to fixed-dose ZDV/3TC + EFV for achieving and maintaining an HIV RNA level <400 copies/mL and an increase in CD4 cells.
[show abstract][hide abstract] ABSTRACT: Durable suppression of replication of the human immunodeficiency virus (HIV) depends on the use of potent, well-tolerated antiretroviral regimens to which patients can easily adhere.
We conducted an open-label, noninferiority study involving 517 patients with HIV infection who had not previously received antiretroviral therapy and who were randomly assigned to receive either a regimen of tenofovir disoproxil fumarate (DF), emtricitabine, and efavirenz once daily (tenofovir-emtricitabine group) or a regimen of fixed-dose zidovudine and lamivudine twice daily plus efavirenz once daily (zidovudine-lamivudine group). The primary end point was the proportion of patients without baseline resistance to efavirenz in whom the HIV RNA level was less than 400 copies per milliliter at week 48 of the study.
Through week 48, significantly more patients in the tenofovir-emtricitabine group reached and maintained the primary end point of less than 400 copies of HIV RNA per milliliter than did those in the zidovudine-lamivudine group (84 percent vs. 73 percent, respectively; 95 percent confidence interval for the difference, 4 to 19 percent; P=0.002). This difference excludes the inferiority of the tenofovir DF, emtricitabine, and efavirenz regimen, indicating a significantly greater response with this regimen. Significant differences were also seen in the proportion of patients with HIV RNA levels of less than 50 copies per milliliter (80 percent in the tenofovir-emtricitabine group vs. 70 percent in the zidovudine-lamivudine group; 95 percent confidence interval for the difference, 2 to 17 percent; P=0.02) and in increases in CD4 cell counts (190 vs. 158 cells per cubic millimeter, respectively; 95 percent confidence interval for the difference, 9 to 55; P=0.002). More patients in the zidovudine-lamivudine group than in the tenofovir-emtricitabine group had adverse events resulting in discontinuation of the study drugs (9 percent vs. 4 percent, respectively; P=0.02). In none of the patients did the K65R mutation develop.
Through week 48, the combination of tenofovir DF and emtricitabine plus efavirenz fulfilled the criteria for noninferiority to a fixed dose of zidovudine and lamivudine plus efavirenz and proved superior in terms of virologic suppression, CD4 response, and adverse events resulting in discontinuation of the study drugs. (ClinicalTrials.gov number, NCT00112047.)
New England Journal of Medicine 02/2006; 354(3):251-60. · 51.66 Impact Factor
[show abstract][hide abstract] ABSTRACT: Tenofovir disoproxil fumarate (DF) is a once-daily nucleotide analogue reverse transcriptase inhibitor.
To evaluate the efficacy and safety of tenofovir DF compared with stavudine in antiretroviral-naive patients.
A prospective, randomized, double-blind study conducted at 81 centers in the United States, South America, and Europe from June 9, 2000, to January 30, 2004. A total of 753 patients infected with HIV who were antiretroviral naive were screened and 602 patients entered the study.
Patients were randomized to receive either tenofovir DF (n = 299) or stavudine (n = 303), with placebo, in combination with lamivudine and efavirenz.
Proportion of patients with HIV RNA levels of less than 400 copies/mL at week 48.
In the primary intent-to-treat analysis in which patients with missing data or who added or switched antiretroviral medications before week 48 were considered as failures, the proportion of patients with HIV RNA of less than 400 copies/mL at week 48 was 239 (80%) of 299 in patients receiving tenofovir DF and 253 (84%) of 301 in patients receiving stavudine (95% confidence interval, -10.4% to 1.5%), exceeding the predefined -10% limit for equivalence. However, equivalence was demonstrated in the secondary analyses (HIV RNA <50 copies/mL) at week 48 and through 144 weeks. Virologic failure was associated most frequently with efavirenz and lamivudine resistance. Through 144 weeks, the K65R mutation emerged in 8 and 2 patients in the tenofovir DF and stavudine groups, respectively (P =.06). A more favorable mean change from baseline in fasting lipid profile was noted in the tenofovir DF group at week 144: for triglyceride levels (+1 mg/dL for tenofovir DF [n = 170] vs +134 mg/dL for stavudine [n = 162], P<.001), total cholesterol (+30 mg/dL [n = 170] vs +58 mg/dL [n = 162], P<.001), direct low-density lipoprotein cholesterol (+14 mg/dL [n = 169] vs +26 mg/dL [n = 161], P<.001), and high-density lipoprotein cholesterol (+9 mg/dL [n = 168] vs +6 mg/dL [n = 154], P =.003). Investigator-reported lipodystrophy was less common in the tenofovir DF group compared with the stavudine group (9 [3%] of 299 vs 58 [19%] of 301, P<.001). The number of bone fractures and the renal safety profile were similar between the 2 groups.
Through 144 weeks, the combination of tenofovir DF, lamivudine, and efavirenz was highly effective and comparable with stavudine, lamivudine, and efavirenz in antiretroviral-naive patients. However, tenofovir DF appeared to be associated with better lipid profiles and less lipodystrophy.
JAMA The Journal of the American Medical Association 07/2004; 292(2):191-201. · 29.98 Impact Factor
[show abstract][hide abstract] ABSTRACT: Resistance to antiretroviral agents remains a leading cause of treatment failure for patients infected with HIV-1.
To describe the efficacy and safety of tenofovir disoproxil fumarate (tenofovir DF) compared with placebo in patients with detectable viral replication despite current antiretroviral therapy.
Randomized, double-blind, placebo-controlled study through 24 weeks. After 24 weeks, all patients received open-label tenofovir DF for the remainder of the 48-week study.
75 North American, European, and Australian HIV clinics.
552 HIV-1-infected adults who were receiving antiretroviral therapy and had stable HIV-1 RNA levels ranging from 400 to 10,000 copies/mL.
Change in HIV-1 RNA level (time-weighted average from baseline through week 24); proportion of patients with grade 3 or 4 laboratory abnormalities and adverse events; and genotypic HIV-1 resistance testing in a separate substudy at baseline, week 24, and week 48.
A statistically significant decrease in HIV-1 RNA level through week 24 (the primary end point) was observed in the tenofovir DF group versus the placebo group (-0.61 log10 copies/mL vs. -0.03 log10 copies/mL, respectively [P < 0.001]; difference, -0.58 log10 copies/mL [95% CI, -0.68 to -0.49 log10 copies/mL]). In a virologic substudy, 94% of 253 patients had plasma isolates expressing reverse transcriptase mutations associated with nucleoside resistance mutations at baseline. Through week 24, the incidence of clinical adverse events was similar between patients receiving placebo and those receiving tenofovir DF (14% vs. 13%). No evidence of tenofovir DF-related toxicity was seen through week 48.
In treatment-experienced patients with suboptimal viral suppression, tenofovir DF significantly reduced HIV-1 RNA level and had a safety profile similar to that of placebo.
Annals of internal medicine 10/2003; 139(5 Pt 1):313-20. · 13.98 Impact Factor
[show abstract][hide abstract] ABSTRACT: Adefovir dipivoxil is a nucleotide analog that has demonstrated effective antiretroviral activity against human immunodeficiency virus (HIV) with once-daily administration.
To determine if adefovir confers antiretroviral or immunologic benefit when added to stable antiretroviral therapy.
Multicenter, 24-week, randomized, double-blind, placebo-controlled study. Enrollment was conducted from June 3, 1996, through May 6, 1997.
Thirty-three US HIV treatment centers.
Of 1171 patients screened, 442 patients infected with HIV receiving stable antiretroviral therapy for at least 8 weeks with plasma HIV RNA greater than 2500 copies/mL and CD4+ cell count above 0.20 x 10(9)/L were randomized.
Patients were randomized to receive either a single 120-mg/d dose of adefovir dipivoxil (n = 219) or an indistinguishable placebo (n = 223). All patients received L-carnitine, 500 mg/d. Open-label adefovir was offered after 24 weeks and was continued until the end of the study.
Changes in HIV RNA from baseline, based on area under the curve and CD4+ cell levels, adverse events, and effect of baseline genotypic resistance on response to adefovir.
Patients assigned to adefovir demonstrated a 0.4-log10 decline from baseline in HIV RNA compared with no change in the placebo group (P<.001), which continued through 48 weeks. CD4+ cell counts did not change. During the initial 24 weeks, elevated hepatic enzyme levels (P<.001), gastrointestinal tract complaints (P<.001), and weight loss (P<.001) were associated with use of adefovir. Between 24 weeks and 48 weeks elevations in serum creatinine occurred in 60% of patients, usually returning to baseline after discontinuation of adefovir. Patients with lamivudine or lamivudine and zidovudine resistance mutations demonstrated anti-HIV effects with adefovir (P< or =.01 vs placebo group).
This study suggests that once-daily adefovir therapy reduces HIV RNA and is active against isolates resistant to lamivudine or lamivudine and zidovudine. Nephrotoxicity occurred when treatment extended beyond 24 weeks but was reversible.
JAMA The Journal of the American Medical Association 01/1999; 282(24):2305-12. · 29.98 Impact Factor
[show abstract][hide abstract] ABSTRACT: Adefovir dipivoxil is a novel nucleotide analogue with several promising in vitro anti-human immunodeficiency virus (HIV) characteristics. To evaluate the safety and efficacy of adefovir dipivoxil monotherapy, a randomized, double-blind, placebo-controlled study was initiated involving 72 subjects with moderately advanced HIV disease. Subjects were randomly assigned in a 2:1 ratio to receive adefovir dipivoxil or placebo as a once-daily oral dose for 6 weeks, followed by 6 weeks of open-label adefovir dipivoxil. Two dose levels were studied (125 mg and 250 mg). Adefovir dipivoxil was determined to be safe and well-tolerated when administered for 12 weeks. At week 6, changes in absolute CD4 T cell levels and HIV-1 RNA levels were significantly greater with adefovir dipivoxil than with placebo. These effects were sustained through 12 weeks of treatment. As determined by standard RNA sequencing techniques, only 1 of the 24 subjects who received adefovir dipivoxil (125 mg/day) developed any genotypic change from baseline.
The Journal of Infectious Diseases 01/1998; 176(6):1517-23. · 5.85 Impact Factor
[show abstract][hide abstract] ABSTRACT: A randomized, double-blind, placebo-controlled, dose-escalation study of adefovir dipivoxil, an oral prodrug of adefovir, was conducted in 36 human immunodeficiency virus (HIV)-infected subjects to evaluate its anti-HIV activity, safety, and pharmacokinetics. Subjects received placebo or one of three dosages of adefovir dipivoxil daily for 14 days. Median decreases in serum p24 antigen of 31% (P = .02), 25% (P = .31), and 30% (P = .01) occurred in each drug-treated group, respectively, compared with an increase of 17% in the placebo group. Median decreases in serum HIV RNA of 0.4-0.6 log10 copies/mL occurred in the drug-treated groups (P = .03), compared with no change in the placebo group. Gastrointestinal complaints and reversible liver transaminase elevations were the most frequently noted adverse events. Decreases in serum free carnitine occurred in each drug-treated group during treatment. After 14 days of dosing, adefovir dipivoxil demonstrated anti-HIV activity and was best tolerated at the lowest dosage studied, 125 mg daily.
The Journal of Infectious Diseases 09/1997; 176(2):406-13. · 5.85 Impact Factor
[show abstract][hide abstract] ABSTRACT: The pharmacokinetics and bioavailability of adefovir [9-[2-(phosphonomethoxy)ethyl]adenine] were examined at two dose levels in three phase I/II studies in 28 human immunodeficiency type 1-infected patients. The concentrations of adefovir in serum following the intravenous infusion of 1.0 or 3.0 mg/kg of body weight were dose proportional and declined biexponentially, with an overall mean +/- standard deviation terminal half-life of 1.6 +/- 0.5 h (n = 28). Approximately 90% of the intravenous dose was recovered unchanged in the urine in 12 h, and more than 98% was recovered by 24 h postdosing. The overall mean +/- standard deviation total serum clearance of the drug (223 +/- 53 ml/h/kg; n = 25) approximated the renal clearance (205 +/- 78 ml/h/kg; n = 20), which was significantly higher (P < 0.01) than the baseline creatinine clearance in the same patients (88 +/- 18 ml/h/kg; n = 25). Since adefovir is essentially completely unbound in plasma or serum, these data indicate that active tubular secretion accounted for approximately 60% of the clearance of adefovir. The steady-state volume of distribution of adefovir (418 +/- 76 ml/kg; n = 28) suggests that the drug was distributed in total body water. Repeated daily dosing with adefovir at 1.0 mg/kg/day (n = 8) and 3.0 mg/kg/day (n = 4) for 22 days did not significantly alter the pharmacokinetics of the drug; there was no evidence of accumulation. The oral bioavailability of adefovir at a 3.0-mg/kg dose was < 12% (n = 5) on the basis of the concentrations in serum or 16.4% +/- 16.0% on the basis of urinary recovery. The subcutaneous bioavailability of adefovir at a 3.0-mg/kg dose was 102% +/- 8.3% (n = 5) on the basis of concentrations in serum or 84.8% +/- 28.5% on the basis of urinary recovery. These data are consistent with preclinical observations in various species.
Antimicrobial Agents and Chemotherapy 11/1995; 39(11):2401-5. · 4.57 Impact Factor
[show abstract][hide abstract] ABSTRACT: Results: A statistically significant decrease in HIV-1 RNA level through week 24 (the primary end point) was observed in the tenofovir DF group versus the placebo group (0.61 log10 cop- ies/mL vs. 0.03 log10 copies/mL, respectively (P < 0.001); dif- ference, 0.58 log10 copies/mL (95% CI, 0.68 to 0.49 log10 copies/mL)). In a virologic substudy, 94% of 253 patients had plasma isolates expressing reverse transcriptase mutations associ- ated with nucleoside resistance mutations at baseline. Through week 24, the incidence of clinical adverse events was similar between patients receiving placebo and those receiving tenofovir DF (14% vs. 13%). No evidence of tenofovir DF-related toxicity was seen through week 48. Conclusion: In treatment-experienced patients with suboptimal viral suppression, tenofovir DF significantly reduced HIV-1 RNA level and had a safety profile similar to that of placebo.