Immune Responses in Patients Treated With Raltegravir (RAG-1/2)

Immune Responses to Neo-Antigens in Patients Treated With Raltegravir: Insights on V(D)J Recombination and RAG-1/2 Recombinase Function

Hypothesis: Treatment with raltegravir does not alter V(D)J recombination or immune responses to neoantigens.

A process known as V(D)J recombination is essential for developing lymphocytes and the specific functioning of the immune system. Raltegravir is the first approved drug of the new integrase inhibitor class of anti-HIV drugs. Integrase inhibitors have been shown in some studies to interfere with DNA cleavage and the activities of RAG-1/2. These studies suggest a potential to affect aspects of both B-cell and T-cell development, therefore, it is important to evaluate the potential effects that integrase inhibitors may have in clinical use. If immunoglobulin and T-cell receptor genes are altered by HIV integrase, then patient lymphocytes will fail to display normal responses to vaccinations.

Study Overview

Status

Withdrawn

Conditions

Intervention / Treatment

Detailed Description

V(D)J recombination is essential for developing lymphocytes and the specific functioning of the immune system. Germline gene coding segments become rearranged to create functional immunoglobulin and T-cell receptor genes by this recombination. The process depends on site-specific cleavage of chromosomal DNA by RAG-1 and RAG-2 recombinase. Two recombination-activating gene proteins (RAG-1/2) in conjunction make up a complex of enzymes that join gene segments of B-cell and T-cell receptor genes. RAG-1 contains most of the V(D)J recombinase active site and RAG-2 is essential in joining DNA segments during V(D)J recombination. RAG-1/2 have similarity in action to other DNA transposases and HIV-1 integrase. These similarities suggest that HIV-1 integrase inhibitors may have the potential to affect aspects of both B-cell and T-cell development.

Induction of primary immune responses to neoantigens involves the generation of specific T-cells and immunoglobulin M (IgM) antibody secreting B-cells. As part of this process, T and B memory cells are also generated, which have specific cell surface receptors to the antigen. On repeat exposure to the antigen, these memory T- and B-cells are triggered to generate rapid and intense secondary responses. During this secondary response, B-cells secrete abundant specific IgG antibodies with greater affinity to the antigen than for the IgM isotope. This memory response is mediated by T-cells with CD45+ RO+ phenotype. These T-cells provide B-cells the help required to generate the specific IgG. Sub-optimal antibody responses are seen in both acquired and hereditary immunodeficiency, which are due to impaired T-cell function including poor T-helper responses to B-cells and defective neo-antigen responses.

An established method to evaluate T-cell function involves testing antibody production to vaccination with phiX174, a stable bacteriophage of E. Coli that is critical in demonstrating T-cell competence. Antibody titers after primary and secondary immunization correlate with abnormal CD4 cell help. Patients with functional B-cells that lack T-cell help show a characteristic failure to switch from IgM to IgG, making this assay essential in the evaluation of V(D)J recombination.

Currently, raltegravir is the only approved integrase inhibitor that targets the integration stage of the HIV-1 lifecycle. The clinical manifestations of raltegravir-related potential adverse effects on V(D)J recombination may be so rare that they may only be observed after large numbers of patients are exposed to this drug. Evaluating the direct in vivo interaction of HIV integrase inhibitors on RAG-1/2 is difficult, therefore the best approach may be to evaluate the potential negative effects on recombinase activity downstream by studying immune function. If gene rearrangements of immunoglobulin and T-cell receptor genes are altered by HIV integrase, then patient lymphocytes will fail to display normal responses to neo-antigen exposure. Since untreated HIV-infected individuals have an impaired ability to respond to new antigens, it is difficult to evaluate the responses to neo-antigens in these individuals. Therefore, to test this hypothesis, it would be best to choose patients with long-term control of HIV that have recovered immune function.

Study Type

Interventional

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Quebec
      • Montreal, Quebec, Canada, H3G 1A4
        • Immune Deficiency Treatment Centre, Montreal General Hospital, McGill University Health Centre

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  1. HIV-1 infected males, as determined by ELISA and Western blot;
  2. >18 years of age;
  3. Current ARV therapy with efavirenz + Truvada® for >52 weeks;
  4. HIV-1 RNA (bDNA) <50 copies/ml for at least 52 weeks;
  5. No history of hepatitis A vaccine, and HAV antibody negative.

Exclusion Criteria:

  1. any immunomodulatory therapy within 24 weeks of screening or during the trial;
  2. any type of vaccine within 24 weeks of screening or during the trial;
  3. current opportunistic infection, malignancy, acute infection, or febrile illness;
  4. history of hypersensitivity to a vaccine, components of a vaccine, or components of a vaccine container.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: 1
raltegravir 400mg bid + Truvada 1 tab qd
VAQTA: 1.0ml IM at weeks 24 & 48; Pneumovax 23: 0.5ml IM at screening; Td ADSORBED: 0.5ml IM at screening; phiX174 bacteriophage: 0.02ml/kg body weight IV at weeks 28, 32, 36, 40.
Other Names:
  • VAQTA;
  • Pneumovax 23;
  • Td ADSORBED;
  • phiX174 bacteriophage
Active Comparator: 2
efavirenz 600mg qhs + Truvada 1 tab qd (or Atripla 1 tab qhs)
VAQTA: 1.0ml IM at weeks 24 & 48; Pneumovax 23: 0.5ml IM at screening; Td ADSORBED: 0.5ml IM at screening; phiX174 bacteriophage: 0.02ml/kg body weight IV at weeks 28, 32, 36, 40.
Other Names:
  • VAQTA;
  • Pneumovax 23;
  • Td ADSORBED;
  • phiX174 bacteriophage

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Percent of patients with phiX174 IgG greater than or equal to 30% of total anti-phiX174 titers
Time Frame: Two weeks after fourth phiX174 immunization
Two weeks after fourth phiX174 immunization

Secondary Outcome Measures

Outcome Measure
Time Frame
Total phiX174 antibody titers
Time Frame: 2 and 4 weeks after each immunization
2 and 4 weeks after each immunization

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Collaborators

Investigators

  • Principal Investigator: Christos M Tsoukas, MD, FRCPC, McGill University Health Centre/Research Institute of the McGill University Health Centre

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2009

Primary Completion (Actual)

August 1, 2011

Study Completion (Actual)

August 1, 2011

Study Registration Dates

First Submitted

November 4, 2008

First Submitted That Met QC Criteria

November 4, 2008

First Posted (Estimate)

November 5, 2008

Study Record Updates

Last Update Posted (Estimate)

April 14, 2015

Last Update Submitted That Met QC Criteria

April 13, 2015

Last Verified

April 1, 2015

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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