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Biomedical subjects

Daniel S Berger

Publications and source records attributed to Daniel S Berger.

16 recordsLinked to original sources
PubMed2005

Early virologic nonresponse to tenofovir, abacavir, and lamivudine in HIV-infected antiretroviral-naive subjects.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Adenine↗
PubMed2005

Abacavir, efavirenz, didanosine, with or without hydroxyurea, in HIV-infected adults failing initial nucleoside/protease inhibitor-containing regimens.

BACKGROUND: Hydroxyurea (HU) is an immunomodulatory agent that has been documented to enhance the antiretroviral activity of nucleoside reverse transcriptase inhibitors, such as abacavir (ABC) and didanosine (ddI), and would be expected to improve virologic efficacy. METHODS: A 48-week, phase IV, multicenter, open-label, proof-of-concept clinical trial was conducted to evaluate second-line, protease inhibitor (PI)-sparing therapy with ABC/efavirenz (EFV)/ddI plus HU or without HU in HIV-infected subjects failing to achieve HIV-1 RNA < or = 400 copies/mL after > or = 16 weeks of treatment with lamivudine/zidovudine or lamivudine/stavudine, plus 1 or 2 PIs. Subjects were assigned to ABC (300 mg twice daily)/ EFV (600 mg once daily)/ ddI (400 mg once daily) plus HU (500 mg twice daily) (n = 30) or this regimen without HU (n = 24). RESULTS: Baseline mean HIV-1 RNA was 3.86 log10 copies/mL and CD4+ cell count was 345 cells/mm3. A similar percentage of subjects in the non-HU arm (58%) and HU arm (53%) completed the study. Intent-to-treat: missing = failure analysis showed no differences in proportions of subjects in the non-HU and HU arms achieving undetectable plasma HIV-1 RNA levels at week 24 (< 400 copies/mL: 58% [14/24] vs 57% [17/30], P = 0.899; < 50 copies/mL (50% [12/24] vs 47% [14/30], P = 0.780). Median change from baseline in CD4+ cell count in the non-HU and HU arms at week 48 was +114 cells/mm3 and -63 cells/mm3 (P = 0.007), respectively. Both regimens were generally well tolerated, although more subjects in the HU arm withdrew prematurely from the study due to adverse events (23% vs 4%). Four cases of possible ABC-related hypersensitivity were observed. CONCLUSION: ABC/EFV/ddI was an effective and well-tolerated second-line regimen for nucleoside/PI-experienced HIV-infected subjects. The addition of HU blunted the CD4+ cell response, did not appear to enhance antiviral activity, and resulted in more treatment-limiting adverse events.

Adult↗
PubMedDate not supplied

Pilot study of once-daily simplification therapy with abacavir/lamivudine/zidovudine and efavirenz for treatment of HIV-1 infection.

OBJECTIVE: The purpose of this pilot study was to explore the efficacy and safety of the abacavir/lamivudine/zidovudine fixed-dose combination tablet administered as two tablets once daily (qd) versus one tablet twice daily (bid) in combination with efavirenz (EFV). METHOD: This was a prospective, randomized, open-label, multicenter study with a 24-week treatment period in 7 outpatient HIV clinics in the United States. Patients currently receiving an initial regimen of abacavir/lamivudine/zidovudine bid plus EFV qd for at least 6 months with HIV-1 RNA <50 copies/mL for at least 3 months and a screening CD4+ cell count > or = 200 cells/mm3 were eligible. Thirty-six patients enrolled, and 35 (97%) completed the study. Participants were randomized to switch to 2 tablets of abacavir/lamivudine/zidovudine qd plus EFV qd (QD arm) or continue current treatment (BID arm) for 24 weeks. RESULTS: Efficacy, safety, and adherence were evaluated. Median baseline CD4+ cell count was 521 cells/mm3. At week 24, HIV-1 RNA <50 copies/mL was achieved for 94% of participants in the QD arm and 89% in the BID arm by intent-to-treat, missing = failure analysis (95% confidence interval for difference: > or = 0.29 to +0.18, p = 1.000). At week 24, median CD4+ cell count change from baseline was +26 cells/mm3 for the QD arm and -39 cells/mm3 for BID arm. One patient randomized to the QD arm met virologic failure criteria (confirmed HIV-1 RNA >120 copies/mL) at week 20 and viral genotype showed M184V. After failure, this patient revealed he never took EFV throughout the entire study after randomization, effectively receiving only abacavir/lamivudine/zidovudine qd alone. Median adherence was slightly higher in the QD arm, although both arms had broad variability and overlapping interquartile ranges. Adverse events were infrequent and occurred with similar frequency between arms; treatment-related adverse events were abdominal pain, flatulence, nausea, headache, and abnormal dreams (1 patient [3%] for each adverse event). No patients withdrew due to adverse events, and no abacavir hypersensitivity reactions were reported. CONCLUSION: In this pilot study of patients suppressed on abacavir/lamivudine/zidovudine bid plus EFV, 94% of participants switching to abacavir/lamivudine/zidovudine qd plus EFV maintained virologic suppression, compared to 89% of participants continuing abacavir/lamivudine/zidovudine bid plus EFV.

Abdominal Pain↗