Immune Response to a Therapeutic HIV Vaccine Followed by Treatment Interruption in Patients With Acute or Recent HIV Infection
Condition: HIV Infections
MeSH terms: Infections; Communicable Diseases; HIV Infections; Acquired Immunodeficiency Syndrome
Study type: Interventional
Phase: Phase 2

Summary: 
      The purpose of this study is to determine whether the HIV vaccine MRKAd5 HIV-1 gag/pol/nef
      followed by treatment interruption can increase immune system function in adults with acute
      or recent HIV infection who have started taking anti-HIV drugs.
    

Detailed description: 
      While the advent of highly active antiretroviral therapy (HAART) has contributed to the
      increasing control of HIV infection and viral replication, ultimate control of HIV infection
      will require the development of effective HIV-specific immunity in HIV infected individuals.
      Therapeutic vaccination within the earliest weeks following acute or recent HIV infection may
      increase the immune system's response to HIV. This study will determine whether MRKAd5 HIV-1
      gag/pol/nef vaccine followed by treatment interruption can maintain viral suppression in
      patients with acute or recent HIV infection.

      The interventional part of the study will last 102 weeks. Participants will be randomly
      assigned to receive either MRKAd5 HIV-1 gag/pol/nef or placebo vaccine at baseline and Weeks
      4 and 26. Participants must remain on HAART from study entry until Week 38. Participants
      whose HIV viral load rebounds two times or more above 500 copies/ml by Weeks 39 to 41 will
      not enter Step 2 of the study. Participants whose viral load drops to 500 copies/ml or less
      by Weeks 39 to 41 will enter Step 2, where they will discontinue HAART for 24 weeks.
      Participants in Step 2 will have plasma HIV viral loads measured every 2 weeks for the first
      4 weeks and weekly for the next 3 weeks. Study participants will continue in Step 2 until
      they experience virologic and immunologic failure or they need to restart HAART for another
      reason; they will then enter Step 3, where they will reinitiate HAART. Step 3 participants
      will continue on HAART until Week 102. A long-term safety follow-up period will occur from
      Weeks 103 to 240.

      Timing of the study visits will be determined by which steps a participant enters. A physical
      exam and blood and urine collection will occur at most study visits throughout the study
      until Week 102. Follow-up phone calls to study participants will occur every 6 months from
      Week 102 until Week 240 to collect long-term safety data, including clinical status, CD4
      count, and medication history. During the long-term safety follow-up, participants will also
      have study visits every 6 months. Visits will include medical and medication history.
    

Intervention name(s): MRKAd5 HIV-1 gag/pol/nef; MRKAd5 HIV-1 gag/pol/nef placebo
Intervention type(s): Biological; Biological
Intervention description(s): 1.5 x 1010 Ad vg/mL, 1.0 mL administered intramuscularly; 1.0 mL administered intramuscularly
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Care Provider)
Primary purpose: Treatment
Keywords: Treatment Interruption; HIV Therapeutic Vaccine; Acute Infection; Acute Retroviral Syndrome