The T Cell Activator of Cell Killing ("TACK") IT ON" STUDY

ConditionHiv
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-89
SponsorUniversity of Toronto

About this trial

Antiretroviral therapy or ART blocks HIV replication reducing plasma viral loads to undetectable levels but has no effect on persistently infected cells in the body, called the virus reservoir. These cells carry infectious HIV capable of restarting HIV replication if therapy is stopped. The reservoir is so stable forcing people to adhere life-long ART. Over 5% of ART adherent individuals continue to have residual non-suppressive viremia (NSV) detected by clinical assays (40-400 copies/ml). Residual viremia reflects a more persistent reservoir and has the potential for increased morbidity. For eg., persistent expression of HIV proteins contributes to inflammation, and can lead to comorbidities. Recently, a novel way to target this reservoir called "TACK" or "Targeted activator of cell killing" is proposed. TACK compounds only target HIV infected cells and directly kill them by inducing a natural killing program (called the inflammasome). Recently the HIV drug, Efavirenz (EFV), which was used to suppress HIV replication for decades, has now been shown to also be a TACK compound. This pilot study will evaluate the impact of Efavirenz (EFV) in reducing HIV persistence by its ability to be a TACK molecule. So in addition to blocking HIV growth, this compound when added to a current ART regimen can kill HIV infected cells in the test tube. We aim to harness this effect to determine whether the addition of EFV to the current ART regimen in people with NSV can suppress the viremia to undetectable levels by killing those cells. NSV represents the "the tip of the iceberg" of those with bigger reservoirs and represents a challenging clinical scenario in dire need of new diagnostic and therapeutic options.

This pilot study will spark larger clinical trials to advance HIV cure strategies, and will provide new tools to improve the clinical management of people living with HIV.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Ability to provide signed written informed consent; age >18 years

Documented HIV diagnosis

Continuous antiretroviral therapy for > 4 years with no issues of adherence

Taking a stable ART regimen, without the inclusion of a protease inhibitor

Disqualifiers

Participants who would have difficulty participating in a trial due to non-compliance

No active medications / illicit drugs that could adversely affect study compliance

Currently prescribed and using EFV as part of ongoing ART treatment regimen for HIV suppression

Currently prescribed a protease inhibitor or pharmacologic booster (cobisistat) as part of current ART regimen

Trial design

Design model

Single group

Treatments tested in this trial

  • Efavirenz 600mg

    Drug

    Efavirenz induces pyroptosis of HIV expressing cells via the CARD8 inflammasome. In contrast to most ART drugs, and in addition to its anti-retroviral effect, EFV also induces intracellular Gag-Pol dimerization and premature HIV protease activation, causing cleavage of the inflammasome protein CARD8. CARD8 activation results in the production of effector molecules that rapidly kill virus-infected cells by pyroptosis. This effect of EFV has been called "TACK" or "T cell activator of cell killing". We aim to harness this effect to reduce residual nonsuppresible viremia (NSV) in people on stable antiretroviral therapy (ART). Participants in this study will receive EFV in addition to their stable ART regimen for two months, during and after which we will monitor plasma HIV RNA and markers of viral persistence and immune activation.

Treatment groups

26 Participants
are divided into 1 treatment group
Group A: Addition of Efavirenz in people with high adherence to ART.Other 1 intervention

Trial outcomes

Primary outcomes

1

Change in plasma viremia (viral copies/ml)

The change in plasma HIV viremia will be compared at baseline (visit 2) versus after 8 weeks of EFV. (visit 7)

Time frame
The change in plasma HIV viremia will be compared at baseline (visit 2) versus after 8 weeks of EFV. (visit 7)

Secondary outcomes

1

The change in plasma HIV viremia will be compared at baseline (visit 2) after 8 weeks of EFV. (visit 7) and after EFV is discontinued (Visits 8 to 10).

1. IPDA - copies/million cells 2. infectious units per million (quantitative viral outgrowth assay), 3. cell-associated RNA (unspliced and polyadenylated RNA);

Time frame
compared at baseline and 8 weeks

Other outcomes

Sponsors and contacts

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University of Toronto

Lead sponsor

Ontario HIV Treatment Network

Collaborator

Maple Leaf Research

Collaborator

Unity Health Toronto

Collaborator