enfuvirtide and amdoxovir

Amdoxovir (2,6-diaminopurine dioxolane; DAPD) is a nucleoside reverse transcriptase inhibitor (NRTI) of human immunodeficiency virus-1 (HIV-1) with activity against wild-type and NRTI-resistant viruses.. ACTG A5118 assessed the antiretroviral activity and safety of DAPD (300 mg orally, twice daily) versus placebo in combination with enfuvirtide (ENF) plus an optimized background (OB) regimen in subjects with failure of two or more antiretroviral (ARV) regimens. The primary endpoints for comparison were time-averaged area under the curve minus baseline (AAUCMB) of plasma HIV-1 RNA concentration at 24 weeks and time to first serious (DAIDS toxicity table Grade > or = 3) adverse event (AE). An unplanned interim review recommended closing enrollment because the study was unlikely to demonstrate a difference between arms. The 18 subjects on study, nine in each arm, were unblinded and allowed to continue study treatment through 48 weeks.. Intention-to-treat analysis showed the median AAUCMB was -0.9 log10 copies/mL (95% CI = -2.2, -.0.1) in the DAPD arm and -0.9 log10 copies/ml (95% CI = -1.1, -0.1) in the placebo arm (P = 0.69). Median CD4+ T-cell increase was 79 cells/mm3 (95% CI =1, 115) in the DAPD arm and 60 (95% CI =1, 101) in the placebo arm (P = 0.45). Time to first serious AE did not differ between arms (P = 0.91). Mild decreases of creatinine clearance were observed with similar frequency between arms; no subject developed lens opacities.. Addition of DAPD to ENF plus OB in advanced subjects with highly resistant virus appeared safe, but did not add statistically significant antiretroviral activity at 24 weeks in this small study.

Topics: Adult; CD4 Lymphocyte Count; Dioxolanes; Drug Resistance, Viral; Drug Therapy, Combination; Enfuvirtide; Female; HIV Envelope Protein gp41; HIV Fusion Inhibitors; HIV Infections; HIV-1; Humans; Male; Middle Aged; Peptide Fragments; Pilot Projects; Purine Nucleosides; Reverse Transcriptase Inhibitors; Treatment Failure; Viral Load

We evaluated the in vitro anti-human immunodeficiency virus type 1 (HIV-1) interactions between 1-beta-D-2,6-diaminopurine dioxolane (DAPD) and enfuvirtide (T-20) against clinical isolates sensitive and resistant to reverse transcriptase and protease inhibitors. Interactions between T-20 and DAPD were synergistic to nearly additive, with combination index values ranging from 0.53 to 1.06 at 95% inhibitory concentrations. These studies suggest that a combination of T-20 and DAPD might be useful in the treatment of antiretroviral drug-experienced patients.

Topics: Anti-HIV Agents; Dioxolanes; Drug Resistance, Viral; Drug Synergism; Enfuvirtide; HIV Envelope Protein gp41; HIV Infections; HIV Protease Inhibitors; HIV-1; Humans; Peptide Fragments; Purine Nucleosides; Reverse Transcriptase Inhibitors