Working… Menu

Safety, Tolerance, Pharmacokinetic and Antiviral Study of Amdoxovir in Combination With Zidovudine in Adults With HIV

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00432016
Recruitment Status : Completed
First Posted : February 6, 2007
Last Update Posted : May 11, 2007
Information provided by:
RFS Pharma, LLC

Brief Summary:

The purpose of this study is to determine the short term safety, tolerance, and antiviral effect of zidovudine (AZT) and amdoxovir (AMDX, DAPD) in combination, and whether the dosage for AZT can be reduced, potentially decreasing side effects, while maintaining antiviral effects.

Study hypothesis: DADP in combination with AZT is safe and effective, and AZT dosing may be reduced, resulting in lower levels of AZT-monophosphate associated with toxicity and maintaining levels of AZT-triphosphate associated with efficacy.

Condition or disease Intervention/treatment Phase
HIV Infections Drug: zidovudine Drug: amdoxovir Procedure: pharmacokinetic sampling Phase 1 Phase 2

Detailed Description:

By 2008, market data suggest that the most commonly prescribed initial treatment regimen for HIV-1 will consist of Truvada® (FTC and tenofovir disoproxil fumarate (TDF)) and Sustiva® (efavirenz (EFV)). A newly formulated drug called Atripla™ containing all three active ingredient has now been approved by the US FDA. Therefore, second line treatments that are currently in development should provide activity against resultant mutations, primarily M184V/I (17%) and much less commonly K65R (0 to 5%), and ideally prevent or be effective against mutations that may occur during second line therapy.

The goal of our program is to identify an AZT/DAPD co-formulation with reduced resistance development and an improved safety profile for the treatment of HIV infections. DAPD has increased sensitivity to M184V/I strains and is active against thymidine analog mutations (TAMs) that may have occurred during previous antiretroviral regimens. AZT offers anti-K65R activity which is believed to be conferred by the 3'-azido moiety containing pseudo-sugar structure and base components of AZT. Hence, AZT could potentially be incorporated to prevent the emergence of the K65R mutation that could limit the long-term benefit of DAPD.

Since nucleoside reverse transcriptase inhibitors (NRTIs) require intracellular phosphorylation to form their active triphosphates, it is preferable to combine NRTIs with different critical kinases. Thymidine kinase-1 is the critical enzyme for the phosphorylation of AZT to its monophosphates. The enzyme involved in the initial phosphorylation of the active metabolite of DAPD, DXG, is guanosine kinase. Nucleotide competition studies conducted using activated human peripheral blood mononuclear (PBM) cells performed with DAPD and AZT with concentrations between 0.1-10 µM demonstrated no competitive inhibition of DXG-triphosphate formation.

The approved dose for AZT is 300 mg bid, and AZT is available as a 300 mg tablet or 100 mg capsule. A previous study in 10 HIV seropositive individuals comparing cellular AZT-mono, di- and tri-phosphate nucleotides at normal and reduced doses, 100 mg tid versus 300 mg bid, demonstrated a significant decrease in plasma AZT and intracellular AZT-monophosphate (AZT-MP) levels, (AZT-MP is associated with toxicity), without significant changes in AZT-triphosphate (AZT-TP) levels in activated PBM cells or antiviral activity. These findings on the effect of AZT dose on intracellular AZT-TP are supported by computer simulations. Maximal predicted cellular levels of AZT-MP and AZT-TP at steady-state, following 200 mg bid and 300 mg bid dosing in 3,000 simulated individuals demonstrated a high overlap between the AZT-TP histograms (> 85 %), suggesting similar efficacies for the 200 and 300 mg bid doses. The low degree of overlap between the AZT-MP histograms (< 8 %) for the two dose regimens, suggests that there may be fewer toxicities with the 200 mg bid dose, supporting our hypothesis that a zidovudine dose of 200 mg bid could reduce the AZT-MP levels without compromising the AZT-TP levels that would be obtained with a 300 mg bid dose.

This 10 day, proof of principle, pharmacokinetic study will provide important information about reduced AZT dosing to support the development of an AZT/DAPD co-formulation which may prevent the emergence of K65R mutations.

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Enrollment : 24 participants
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Double
Primary Purpose: Treatment
Official Title: A Randomized, Placebo-Controlled Study to Evaluate Safety, Tolerance, Pharmacokinetics and Antiviral Activity of Amdoxovir and Zidovudine in Untreated HIV-1 Infected Subjects Currently Untreated
Study Start Date : February 2007
Actual Study Completion Date : May 2007

Resource links provided by the National Library of Medicine

MedlinePlus related topics: HIV/AIDS
Drug Information available for: Zidovudine

Primary Outcome Measures :
  1. Proportion of subjects in each arm with Grade 3 or greater treatment emergent adverse events (AE)
  2. Plasma Cmax, Cmin, tmax, AUC0→τ, AUC0→∞, t1/2, CL/F of DAPD and AZT in each group at Days 1 and 10
  3. Intracellular Cmax, Cmin, tmax, AUC0→τ, AUC0→∞, and t1/2 of DXG-TP, -MP and -DP and AZT-TP, -MP, and -DP at Days 1 and 10

Secondary Outcome Measures :
  1. Change in viral load (plasma HIV-1 RNA) from Baseline through Day 10
  2. Correlate intracellular DXG-TP and AZT-TP with viral response, as measured by plasma HIV-1 RNA
  3. Quantitate DXG, AZT, and GAZT in urine with and without DAPD
  4. Characterize viral rebound (plasma HIV-1 RNA) following drug discontinuation for 48 hr
  5. Measure CD4+ count changes from Baseline to Day 10

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • HIV-infection
  • Antiretroviral therapy naïve, or if experienced, no treatment within 90 days of study screening and plan to remain off therapy for the duration of the screening and study treatment period
  • HIV-1 RNA ≥ 5,000 copies/mL within 30 days of study Day 1
  • CD4+ count ≥ 200 cells/mm³ within 30 days of study Day 1
  • Agree to the use of two forms of adequate contraception for women, one form for men
  • Estimated creatinine clearance > 80 mL/min
  • Serum creatinine < 1.5 g/dL
  • Able to give written informed consent prior to study start and adhere to study requirements

Exclusion Criteria:

  • Active alcohol or drug use which in the opinion of the Investigator will likely compromise adherence to the study requirements
  • A positive urine test for amphetamines, cocaine, and/or opioids
  • Currently has any active AIDS defining illness (Category C condition according to the CDC Classification System for HIV Infection 1993)
  • Any active clinically significant disease or findings during screening of medical history or physical examination that in the Investigator's opinion would compromise the outcome of the study
  • Receiving oral concomitant antiviral or prophylactic drugs for opportunistic infections within 30 days prior to study entry
  • Receiving concomitant treatment with nephrotoxic drugs (e.g., aminoglycosides [tobramycin, gentamicin, and amikacin], amphotericin B, vancomycin, cidofovir, foscarnet, cis-platinum, pentamidine), or competitors of renal excretion (e.g., probenecid) within 30 days of study entry
  • Visual abnormalities (e.g. cataracts, macular degeneration) other than non-organic decreased visual acuity
  • Receiving concomitant treatment with immunosuppressive drugs within 30 days prior to study entry
  • Diabetes mellitus Type 1 or 2 which is being treated or not with any anti-diabetes agents
  • Current significant gastrointestinal, renal, hepatic, bronchopulmonary, biliary, neurological, cardiovascular, oncologic, allergic, or ophthalmologic diseases including history of cataracts/lens opacities
  • The following laboratory values performed within 30 days prior to study Day 1:

    • Hemoglobin < 9.0 g/dL for men; 8.0 g/dL for women
    • Platelet count < 75,000 cells per mL
    • Absolute neutrophil count < 1,000 cells per mL
    • AST, ALT, alkaline phosphatase, and amylase > 3 x ULN
    • Random or fasting glucose > 121 mg/dL
    • Serum lipase > 1.5 x ULN
    • Urinalysis ≥ 2+ proteinuria and ≥ 2 cellular casts per high powered field (HPF)
  • Active acute hepatitis A and/or chronic hepatitis B or C with detectable viremia
  • Subjects with clinical or laboratory evidence of significantly decreased hepatic function or decompensation, irrespective of liver enzyme levels (INR > 1.3 or albumin < 30 g/l or bilirubin > 2.5 x ULN)
  • Pregnant women
  • Breastfeeding women

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00432016

Layout table for location information
Hospital Privado Modelo
Buenos Aires, Argentina, B1602DBG
Sponsors and Collaborators
RFS Pharma, LLC
Layout table for investigator information
Principal Investigator: Carlos Zala, MD Hospital Privado Modelo
Publications automatically indexed to this study by Identifier (NCT Number):
Layout table for additonal information Identifier: NCT00432016    
Other Study ID Numbers: RFS-AMDX-203
First Posted: February 6, 2007    Key Record Dates
Last Update Posted: May 11, 2007
Last Verified: May 2007
Keywords provided by RFS Pharma, LLC:
Treatment Naive
Additional relevant MeSH terms:
Layout table for MeSH terms
HIV Infections
Lentivirus Infections
Retroviridae Infections
RNA Virus Infections
Virus Diseases
Sexually Transmitted Diseases, Viral
Sexually Transmitted Diseases
Immunologic Deficiency Syndromes
Immune System Diseases
Molecular Mechanisms of Pharmacological Action
Reverse Transcriptase Inhibitors
Nucleic Acid Synthesis Inhibitors
Enzyme Inhibitors
Anti-Retroviral Agents
Antiviral Agents
Anti-Infective Agents
Anti-HIV Agents