Effect of intensification of long-term highly active antiretroviral therapy (HAART) with raltegravir on proviral HIV-1 DNA in blood and gut associated lymphoid tissue (GALT):

a randomized, placebo controlled trial

Jason Brunetta1, Colin Kovacs1,2,Tae Wook-Chun3, Janet Raboud2,4, Desheng Su4, Mario Ostrowski2,5,Gabor Kandel 2,5, Graham Smith 1, Rupert Kaul 2,4, Roberta

Halpenny 1, Duncan Chege2, Mona Loutfy 1,2,5

1Maple Leaf Medical Clinic, Toronto, Ontario, Canada; 2University of Toronto, Toronto, Ontario, Canada; 3Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA; 4Division of Infectious Diseases, University Health Network, Toronto, Ontario,

Canada; 5 St. Michael’s Hospital, Toronto, Ontario, Canada

Conflict of Interest Disclosure

Funding for this project was provided by a Research Grant from Merck Frosst Canada

Ltd.

Background Eradication of HIV remains elusive due to the persistence of viral

reservoirs.

- The gut-mucosal compartment is an important viral reservoir

- Viral reservoirs mainly consist of long-lived and latently infected CD4+ T cells

New HAART drug classes may help target these latently infected

reservoirs. E.g;

- Integrase inhibitors (e.g. raltegravir)

- Entry/fusion inhibitors

Background Recent studies examining raltegravir intensification therapy failed to

show a reduction in plasma HIV RNA [Reviewed in Schulze, et al JID 2011]

- However, changes in plasma viremia may not reflect changes in the mucosal reservoir.

1 recent study suggested no reduction in proviral DNA in the gut

[Yukl et al, AIDS 2010]. However, this pilot study:- was an open-label study without controls

- had a relatively small sample size (n=7)

- intensified participants with raltegravir for a brief period (12 weeks).

HYPOTHESIS

Raltegravir intensification in long-term suppressed individuals will decrease blood and sigmoid CD4+ T cell HIV proviral levels.

Methods Study design

– A prospective, double-blind, placebo-controlled randomized controlled trial (ClinicalTrials.gov # NCT00520897)

Enrolled participants

– HIV-infected individuals recruited from the Maple Leaf Medical Clinic

Inclusion criteria

– Sustained virologic suppression (<50 viral copies/ml) for over 4years– Participant must be on first standard HAART with 2-3 NRTIs and 1-2 PIs or

an NNRTI for at least four years Exclusion criteria

– Active AIDS-defining illness in past six months– Abnormal clinical laboratory test results at screening

Methods – Study schematic

Raltegravir-intensification

(400mg twice/day)

Placebo

Randomize

n=12

24 HIV+ patients fully suppressed on

HAART

4w 8w 12w 16w 28w 40w 48w

Primary analysis at week 48

n=12

Measured Outcomes:- Blood & sigmoid HIV-1 proviral DNA in CD4+ T cells- Blood CD4+ T cell counts

48w 0w Sigmoid biopsy

Blood phlebotomy

4w 8w 12w 16w 28w 40w 48w

48w 0w Sigmoid biopsy

Blood phlebotomy

Study Endpoints Primary endpoint

Determine if 48 weeks of raltegravir intensification in long-term virologically suppressed participants on HAART is associated with a change in HIV-1 proviral DNA in blood and sigmoid CD4+ T cells

Secondary endpointDetermine effect of raltegravir intensification on blood CD4+ T cell populations

Laboratory methods

BloodPhlebotomy

Ficolldensity

separationPBMC/Sigmoid

CD8Depletion

Real time PCR:HIV-1

Proviral DNA amplification &

quantitation

Sigmoidoscopy

0.5 & 1.0 ug/ml Collagenase-IItissue digestion

(30 min each)

CD4+ T cell counts done on whole blood (counts/mm3) using FACS

HIV-1 DNA copy number per 1x106 CD4+

T cells reported(LOD: 2.6 copies)

PBMC

GALT

Results – Table 1

Baseline clinical and demographic characteristics were similar between the groups.

Results

TreatmentMedian

Baseline proviral load (log10)

Medianw48 proviral load

(log10)

Raltegravir group 3.05 3.11

Placebo group 2.86 2.91

No difference in blood HIV DNA proviral load between groups at week 48 (p=0.62)p from ANCOVA

Results

TreatmentMedian

Baseline CD4 count (cells/mm3)

Medianw48 CD4 count

(cells/mm3)

Raltegravir group 665 690

Placebo group 610 700

No difference in blood CD4+ T cell counts between groups at week 48 (p=0.25)p from ANCOVA

Results

TreatmentMedian

Baseline proviral load (log10)

Medianw48 proviral load

(log10)

Raltegravir group 3.10 2.84

Placebo group 3.20 3.08

No difference in sigmoid HIV DNA proviral load between groups at week 48 (p=0.74)

p from ANCOVA

Summary In virologically suppressed patients on HAART, 48 weeks of

raltegravir-intensified therapy, as compared to placebo,- did NOT result in decay of blood or sigmoid HIV DNA in CD4+ T-lymphocytes

- had NO impact on blood CD4+ T cell populations

Extending raltegravir intensification out to 96 weeks also did NOT

result in any significant decrease in HIV DNA in blood or sigmoid

CD4+ T lymphocytes (data not shown)

Additional novel approaches are required to help reduce the latent

viral reservoir.

Acknowledgments All the patients

Research staff at Maple Leaf Medical Clinic- For working on this project

Dr. Kandel for sigmoid biopsies

HIV Statistical Analytical Group at UHN- Dr. Janet Raboud’s team

Duncan Chege for analytical work, work on presentation & slides

Funders