Showing posts with label reservoirs. Show all posts
Showing posts with label reservoirs. Show all posts

Wednesday, May 30, 2012

HIV Cure Related Studies Currently Enrolling



IMMUNE BASED THERAPIES


Phase 1 Dose Escalation Study of Autologous T-cells Genetically Modified at the CCR5 Gene by Zinc Finger Nucleases in HIV-Infected Patients
The purpose of this research study is to find out whether "zinc finger" modified CD4+ T-cells are safe to give to humans and find how "zinc finger" modified T-cell affects HIV. Five different cohorts with different patient characteristics are being recruited

Dose Escalation Study of Cyclophosphamide in HIV-Infected Subjects on HAART Receiving Sangamo's SB-728-T
The purpose of the study is to evaluate the safety, tolerability and effect on HIV viral load, of escalating doses of cyclophosphamide administered 1 day prior to SB-728-T infusion. It is hoped that cyclophosphamide could improve engraftment of modified T cells.

High-Dose Chemotherapy With Transplantation of Gene-Modified Stem Cells for High-Risk AIDS-Related Lymphoma
Patient stem cells will be mobilized with induction chemotherapy (R)-ICE and G-CSF. If sufficient cells can be mobilized, patients will be treated with high-dose chemotherapy and a transplant of autologous CD34+ cells transduced with an antiviral vector (M87o). If autologous CD34+ yield is insufficient, allogeneic gene-modified cells will be given, if a compatible donor is available. To minimize risk of transplant failure, a second unmodified CD34+ cell transplant will be given one week after the first transplant.


ACE Inhibitors to Decrease Lymphoid Fibrosis in Antiretroviral-Treated, HIV-infected Patients: A Pilot Study
The investigators propose a proof-of-concept, pathogenesis-oriented, randomized, placebo-controlled pilot study to assess whether the addition of an angiotensin converting enzyme (ACE) inhibitor to standard Highly Active Antiretroviral Therapy (HAART) reverses lymphoid fibrosis, and whether this leads to more effective HIV-specific host immune responses and an accelerated clearance of the latent reservoir.

Safety and Efficacy Study of AGS-004 During Analytical Treatment Interruption
The purpose of this study is to determine the safety and effectiveness of AGS-004, an immune therapy, for HIV-infected individuals. Safety and effectiveness will be tested while the individuals are both taking antiretroviral therapy (ART) medication and interrupting ART medication.
http://clinicaltrials.gov/ct2/show/NCT01069809?term=HIV+reservoir&recr=Open&rank=19

Allogeneic Transplant in HIV Patients (BMT CTN 0903)
The rationale for this trial is to demonstrate the feasibility and safety of allogeneic HCT for patients with chemotherapy-sensitive hematological malignancies and coincident HIV-infection. In particular, the trial will focus on the 100-day non-relapse mortality as an indicator of the safety of transplant in this patient population. Correlative assays will focus upon the incidence of infectious complications in this patient population, the evolution of HIV infection and immunological reconstitution. Where feasible (and when this can be accomplished without compromise of either the donor quality or the timeliness of transplantation), an attempt will be made to identify donors who are homozygotes for the delta32 mutation for CCR5.
http://clinicaltrials.gov/ct2/show/NCT01410344


 A randomized, double blind, phase IIB study testing the efficacy and safety of AGS-004 on host control of HIV replication during analytical treatment interruption

In this randomized, double blind, phase 2B trial, researchers will administer ASS-004 intradermally — into the skin — every four weeks at a dose of 1.2 x 10 7. In order for researchers to test AGS-004, participants will undergo a clinically controlled short-term analytical treatment interruption.
AGS-004 is created from a person’s own dendritic cells—white blood cells that stimulate the body’s immune system — and a sample of their HIV virus. This is the first experimental treatment designed from a person’s HIV genetic material and their body’s cells. Researchers believe that this study immunotherapy will boost anti-HIV immune responses in order to partially or totally control viral replication in the absence of ART or at least to significantly delay/limit the use of ART.


THERAPEUTIC HIV VACCINES



A Phase Il of a Therapeutic, Recombinant, Biologically Active HIV-1 Tat Protein Vaccine in HIV-Infected, Anti-Tat Negative, ARV-Treated Adult Volunteers (ISS T-003)
Tat is a key HIV regulatory protein produced very early after infection, prior to virus integration, and necessary for viral gene expression, cell-to-cell virus transmission and disease progression. Previous studies in natural HIV infection, indicated that the presence of a Tat-specific immune response correlates with a lower incidence and reduced risk of progression to AIDS as compared to anti-Tat negative individuals suggesting that an immune response to Tat may exert a protective role and control the progression to AIDS in vivo. Moreover Tat is conserved in its immunogenic regions (both B and T cell) among all subtypes. subtypes. Recent data, in fact, indicate an effective cross-clade recognition of clade B strain-derived (BH-10) Tat protein from the HTLV-IIIB lab-adapted virus strain (Buttò, 2003), which was isolated about 20 years ago (Ratner, 1985), by sera from individuals infected with viruses circulating at the present in Italy and in Africa, thus reflecting the high degree of conservation of the corresponding Tat regions and providing strong formal evidence that a Tat-based vaccine may indeed be used in the different geographic areas of the world, since it is capable of inducing a broad immune response against different virus clades. Based on this rationale and on the positive results of preclinical (Cafaro, Nat Med 1999) and phase I preventive and therapeutic clinical trials with Tat protein (ISS P-001 and ISS T-001, respectively) (Ensoli AIDS 2008, Vaccine 2009; LongoVaccine 2009; Bellino RRCT, 2009) a phase II therapeutic, open label, clinical study with Tat protein (ISS T-002, ClinicalTrials.gov NCT00751595) was sponsored by ISS and activated in 11 clinical sites in Italy in HIV-infected HAART-treated subjects.In this study, subjects are randomized into two arms to receive 3 or 5 vaccinations monthly; each arm is composed of two treatment groups, receiving 7, 5 or 30 µg of Tat, respectively. Preliminary results obtained from 87 subjects enrolled in the phase II trial ISST-002 ongoing in Italy, indicate that Tat vaccination is safe, immunogenic and capable of reducing the immune dysregulation which persists despite HAART in treated individuals, opening new avenues for a most effective treatment of HIV/AIDS (Ensoli et al,PLoS ONE 2010).

Immunomodulating Therapy and Improved Vaccination Responses by Cox-2 Inhibitor in HIV-infected Patients (OUSCOX2)
Chronic immune activation is a central feature of HIV-infection, and the degree of activated T-cells is a better predictor of disease progression and mortality than plasma viral load. The study hypothesis is that the anti-inflammatory substance etoricoxib will dampen chronic immune activation and improve the effect of T-cell dependent vaccines in HIV-1 infected patients.
The aim of the present study is to explore the efficacy of the study drug on markers of immune activation and vaccine responses, as well as safety of the study drug, in HIV-infected patients not receiving antiretroviral therapy.

Safety and Tolerability of a Therapeutic DNA Dendritic Cell Vaccine in HIV-Infected Children, Adolescents, and Young Adults
The therapeutic DNA vaccine, DermaVir, represents an immunization strategy that targets lymph node dendritic cells. Because of the high percentage of naive CD4 cells in children and adolescents, the potential for effective new HIV-specific CD4 cell responses may be more achievable in children than in adults. The primary purpose of this study is to evaluate the safety and tolerability of DermaVir in children and young adults.

Safety and Immune Response Assessment Study of Killed-whole HIV-1 Vaccine (SAV001-H) in Chronic HIV-1 Infected Patients
The purpose of this study is to examine the safety, tolerability, and immune response to killed-whole HIV-1 (SAV001-H) vaccine as a primary vaccination regimen in HIV infected individuals.

A Study to Evaluate the Safety of the HIV-1 Vaccine MVA-B in Chronic HIV-1 Infected Patients Successfully Treated With HAART 
30 treated chronic HIV-1 infected patients with CD4+ cell counts above 450 cells/ mm3 will be randomized 1:2 to receive placebo (n=10) or vaccine (n=20) at week 0, 4 and 16 and will be observed at the Investigation Unit of the study site for one hour following vaccination. At week 24 they will stop their HAART until the end of the study.


Redirected High Affinity Gag‐Specific Autologous T Cells for HIV Gene Therapy
This research study uses a T cell receptor (TCR) protein specific for HIV (SL9 TCR) and adds it to the CD8 T‐cells in the laboratory in order to help the CD8 T‐cells recognize the constantly changing HIV virus and make it able to fight HIV more efficiently. TCR stands for T cell receptor TCRs are found on the surface of T cells and allow the T cells to recognize other cells. Laboratory studies have shown that when CD8 T‐cells are modified with SL9 TCRs, they kill cells that are infected with HIV better than normal CD8 T‐cells can. On the basis of these laboratory results, there is the potential that SL9 TCRs may work in people infected with HIV and improve their immune system by killing HIV infected cells and thus may help control HIV infection.
Two different SL9 TCRs will be tested in this study, WT‐gag‐TCR and α/6‐gag‐TCR. Two different types of SL9 TCRs are being used in this research study because the laboratory studies suggest that the different SL9 TCRs will function differently depending on the amount of virus in your body. A goal of this clinical study is to test the effects of infusions of either SL9 TCR in the presence or absence of a viral load.
http://clinicaltrials.gov/ct2/show/NCT00991224?term=hiv-infected+vaccine&recr=Open&rank=32

Phase I/IIa Dose-escalation Clinical Study of VAC-3S
The purpose of this trial is to evaluate the safety and immunogenicity of the therapeutic vaccine candidate VAC-3S in HIV-1 infected patients under AntiRetroviral Therapy (ART) with undetectable viral loads.
http://clinicaltrials.gov/ct2/show/NCT01549119


Safety and Immunogenicity of HIVAX in HIV-1 Infected Subjects (GCHT01)
This study is to test a therapeutic HIV-1 vaccine (HIVAX™) in HIV-1 infected subjects. The safety and immune responses will be studied in vaccine recipients. The anti-viral effect of HIVAX vaccine will be monitored during a 12-week treatment interruption phase.
http://clinicaltrials.gov/ct2/show/NCT01428596



RESERVOIR RELATED

The Effect of Vorinostat on HIV RNA Expression in the Resting CD4+ T Cells of HIV+ Pts on Stable ART
The purpose of this study is to compare HIV RNA expression within resting CD4+ cells in HIV-infected patients on stable ART before and after a single exposure to Vorinostat (VOR).
Hypotheses: The frequency of detectable HIV RNA expression within resting CD4+ T cells will increase after VOR exposure in vivo.

The Study of Gut Associated Lymphocytes in HIV and HCV/HIV Co-infected Patients
The purpose of this research study is to explore what role immune cells within the gut (the sigmoid colon) have locally and on the immune system of patients infected with HCV, HIV or HCV/HIV co-infection.

Safety and Effect on HIV Transcription of Vorinostat in Patients Receiving Suppressive Combination Anti-retroviral Therapy
The objective of the study is to assess the safety and ability of vorinostat, a drug currently licensed for the treatment of a type of lymphoma, to 'turn on' dormant HIV infected CD4 T-cells.

Tissue Drug Levels of HIV Medications:
The aim of this study is to find out why HIV continues to make copies in people taking HIV drugs. The Investigators want to know if the medications most people use to treat HIV do not completely stop the virus from making additional copies of HIV.

IntensVIH: Impact Of Therapy Intensification By An Integrase Inhibitor +/- CCR5 Inhibitor On The Lymphoid Reservoir For Hiv-1 
To determine the efficacy of adding Isentress®, with or without Celsentri®, to effective conventional antiretroviral therapy (comprising at least 2 reverse transcriptase inhibitors and one boosted protease inhibitor), on residual HIV replication and blood cell and gut-associated lymphoid tissue reservoirs (reverse transcriptase inhibitors: RTIs, boosted protease inhibitors: PI/r).
To evaluate the effect of therapy intensification by means of an integrase inhibitor with or without CCR5 inhibitor treatment on the lymphoid reservoir in patients chronically infected with HIV-1, successfully treated with "conventional triple therapy", measured by:
·        residual plasma replication between 0 and 50 copies/ml
·        intracellular HIV RNA levels in circulating lymphocytes (PBMC) and lymphocytes in gut-associated rectal lymphoid tissue (RL).
·        proviral HIV DNA levels in PBMC and RL.

The Use of Leukapheresis to Support HIV Pathogenesis Studies
A more complete understanding of the relationship between inflammation and viral persistence is necessary before more rationale studies of HIV eradication can be designed. Also, a well validated high through-put virologic assay needs to be developed that can estimate the size of the latent reservoir. Since the level of replication competent virus in long-term treated patients (and in elite controllers) is very small (< 1% of CD4 cells harbor HIV), large numbers of CD4+
T
ce
lls most be obtained from study participants in order to routinely isolate and quantify virus persistence.

Interferon Alpha 2b Intensification in HIV-Positive Individuals on Antiretroviral Therapy
Earlier studies of HIV-infected individuals who were not on any ART showed that interferon reduced the level of HIV in the blood. Researchers are interested in determining whether PEGINTRON therapy will also reduce the residual low levels of HIV in patients who are already taking ART.


Viral Load in Blood and Lymph Tissues of HIV-Infected Individuals
Our laboratory has previously demonstrated that lymph nodes are a major reservoir for human immunodeficiency virus (HIV) and a major site of active virus replication in infected individuals(1-3). There is at least a 10 fold greater viral burden per given number of CD4+ T lymphocytes obtained from the lymph nodes versus the peripheral blood in the same infected individual. These data have been accumulated predominantly in individuals with progressive generalized lymphadenopathy (CDC Class A1 and A2). It is unclear at present whether this pattern holds true for all categories of HIV infected individuals. We have proposed that the seeding of lymph nodes by HIV early in the course of HIV infection and the persistent production of virus in lymph nodes throughout the course of infection are major factors in the pathogenesis of HIV in virtually all infected individuals. 

The " Extreme " Cohort (CODEX)
This cohort will allow common research projects with common fundings and a better visibility both for clinicians who see patients with unusual phenotypes and for international research. Such a cohort will be unique in the world by its size and the presence of these two complementary groups of patients. The two main objectives for the " Extreme " cohort (CODEX) are clinical and immunovirological. The investigators wish to precise the impact of a prolonged untreated HIV infection, to describe the frequency of the "immunological escapes" (CD4 T cell decrease) or "virological escapes" (permanent or transient viral load increase). The investigators wish to study the genetic characteristics of the patients and those of their viruses, the innate and adaptative immune responses directed against HIV and other viruses, the consequences of inflammation, and the characteristics of the loss of control.


Role of extended-released niacin on immune activation in HIV-infected patients treated with antiretroviral therapy: a proof-of-concept study



This pilot study will evaluate the effect of a drug called Niaspan®, an extended-release form of niacin (ER niacin), in individuals living with HIV who are on antiretroviral therapy (ART). Researchers will examine the ability of an oral form of ER niacin to reduce immune activation and increase CD4 cells in persons with sub-optimal immune responses despite sustained virologic suppression from ART.
Study researchers believe that by regulating an amino acid called tryptophan, niacin may decrease T cell immune activation which may enhance CD4 recovery and improve neurocognitive functions. The effect of administering ER niacin in combination with ART will be measured against a regimen of ART alone.

Impact of HIV infection and antiretroviral therapy on mucosal and systemic memory CD4 T cells

This study will assess the impact of HIV infection and antiretroviral therapy on mucosal (gut) and systemic memory CD4 T cells in treatment-naïve HIV-positive individuals within six months of infection. Researchers believe this study will generate data to better understand how HIV harms the body and how they can use this information to better design HIV therapies and vaccines in the future.





Monday, March 12, 2012

Getting HIV Out of its Hiding Places - Reports from CROI 2012



 NATAP/CROI: HIV Eradication Study by DMargolis with Cancer Drug

Here is link to webcast of the oral session at CROI called HIV Persistence, Latency, and Eradication where Dr David Margolis presented the results of the study he conducted which is discussed below:

from Jules Levin: The drug Zolinza used in this study appears to have been able to "disrupt HIV latency, a signifucant step in eradication", flush out HIV RNA from latently infected resting CD4 cells, which is considered perhaps the major HIV reservoir that remains after successful HAART reduces & sustains HIV viral load to below 50 copies. This study has been a while in the making, years in fact, previously another drug was tried but unsuccessfully, and this drug & experiment appears to be successful, at least at first blush. It remains to be seen what the ultimate success will be in controlling HIV with this approach as well as with other approaches. So this appears to be a hopeful & successful step, but with more steps to go.

Zolinza May Help Reduce Latent HIV Reservoirs In People With HIV (CROI 2012)

aidsbeacon.com
Published: Mar 9, 2012 7:14 pm
Results from a recent small study indicate that Zolinza, a drug currently approved to treat a certain type of lymphoma, may successfully reduce the size of the latent HIV reservoir in HIV-positive adults taking antiretrovirals.
“This is a proof of concept demonstrating that latency can be targeted. This is a significant step towards eradication of HIV infection,” said Dr. David Margolis, a professor of medicine at the University of North Carolina at Chapel Hill and lead author of the study.
“The ability of this drug to deplete latent infection remains to be established and would be the next immediate goal of our work,” he added.
Dr. Margolis urged more research into the ability of Zolinza and other drugs to eliminate or reduce the latent HIV reservoir as a regular part of HIV infection management.
The results were presented yesterday at the 19th Conference on Retroviruses and Opportunistic Infections (CROI) in Seattle.
Latent HIV is HIV that is not actively replicating. Instead, it lies dormant, often in immune system cells with long lifespans, such as memory cells (cells that “remember” bacteria and viruses from past infections so they can be effectively fought again). Since antiretroviral drugs usually work by blocking replication, they do not work on latent HIV.
Eradicating latent HIV is a top priority for scientists attempting to cure HIV, and several drugs are currently being tested for their ability to reduce or eliminate this hidden reserve of the virus.
Zolinza (vorinostat) is a histone deacetylase (HDAC) inhibitor, a type of drug currently used as mood stabilizers and anti-epileptic treatments. More recently, HDAC inhibitors have been investigated as anti-cancer agents, and Zolinza is approved to treat a type of lymphoma.
Research has shown that Zolinza successfully activates latent HIV in infected cells in the laboratory. Once latent HIV is activated and begins replicating, scientists hope it will become susceptible to elimination with antiretroviral therapy (see related AIDS Beacon news).
In this study, researchers investigated whether the drug is capable of activating latent HIV in adults whose HIV is well-controlled with antiretroviral therapy.
The study included six HIV-positive participants, each of whom received a single dose of 400 mg Zolinza. All participants had undetectable amounts of HIV in the blood.
Researchers measured the amount of HIV RNA, a marker of latent HIV, in resting CD4 (white blood) cells, a type of immune cell that is targeted by HIV and is thought to be a major source of latent HIV. The researchers measured the HIV RNA both before and within eight hours after giving the participants Zolinza.
Results showed that the amount of HIV RNA measured in participants’ resting CD4 cells increased an average of five-fold after they took Zolinza. According to the study authors, this indicates that Zolinza successfully reactivated the latent HIV in these cells.
There was no increase in the amount of HIV in participants’ blood due to the treatment.
Participants reported no serious side effects, and none of the side effects were attributed to taking Zolinza.
-------------------
CROI ABSTRACT

Administration of Vorinostat Disrupts HIV-1 Latency in Patients on ART
N Archin1, A Liberty1, A Kashuba1, S Choudhary1, J Kuruc1, M Hudgens1, M Kearney2, J Eron1, D Hazuda3, and David Margolis*1
1Univ of North Carolina at Chapel Hill, US; 2HIV Drug Resistance Prgm, NCI-Frederick, MD, US; and 3Merck Res Labs, West Point, PA, US
Background:  Despite ART, proviral latency of HIV-1 remains a principal obstacle to curing the infection. Inducing the expression of latent genomes within resting CD4+ T cells is a primary strategy to clear this reservoir. While histone deacetylase (HDAC) inhibitors such as suberoylanilide hydroxamic acid (SAHA or vorinostat [VOR]) can disrupt HIV-1 latency in vitro, the utility of this approach has never been directly proven in a study of HIV-infected patients.
Methods:  HIV+ participants on ART, stably <50 copies/mL, maintained ART, and resting CD4+ T cells are obtained via leukapheresis. If an increase in the frequency of HIV RNA expression was observed following ex vivo exposure of resting CD4+ T cells to VOR, patients received 400 mg VOR at separate visits. First, VOR pharmacokinetics were measured. Then biomarker measures of HDAC inhibition in peripheral blood mononuclear cells (PBMC), and measurements of unspliced HIV gag RNA in pools of 1 million resting CD4+ T cells were quantified during VOR exposure.
Results:  Five men have been studied (medians: age 45; CD4 count 562 cells/µL; 4 years of ART). VOR has been well tolerated with no adverse events greater than Grade I, and no adverse events attributable to VOR. Measures of PBMC cellular histone acetylation, and chromatin-bound histone acetylation at the human p21 gene promoter increased more than 2-fold within 8 hours of VOR dosing. VOR PK was comparable to oncology studies with Cmax 263 ng/mL (range 204 to 301) and Tmax 2 hours (range 1 to 4). In each participant, HIV RNA levels increased significantly in pools of resting CD4+ cells obtained after VOR dosing compared to baseline measurements (mean 5-fold, range 3- to 10-fold).
Conclusions:  We measured HIV RNA expression directly within circulating resting CD4+ T cells of patients in whom viremia was fully suppressed by ART. In all patients studied thus far, a single dose of VOR rapidly increased both biomarkers of cellular acetylation, and simultaneously induced up to a 10-fold increase in HIV RNA expression in resting CD4+cells. This is the first demonstration that a molecular mechanism known to enforce HIV latency can be specifically and successfully targeted in man, resulting in readily measureable HIV RNA expression in highly purified, resting CD4+ T cells. Our study provides proof-of-concept for HDAC inhibitors as a therapeutic class to directly attack and potentially eradicate latent HIV infection, and defines a precise approach for evaluating such strategies.


Wednesday, March 07, 2012

Pre-CROI HIV Cure Review Workshop Organized by Community Advocates- Meeting Notes



Thanks to Siegfried Schwarze, a research activist from  Germany, for writing down these notes from the meeting we had this past Sunday, March 4, 2012 in Seattle prior to CROI-2012.
****************************************************************************

Sometimes the most important events don‘t take place at the conference itself but rather at  the surrounding workshops. This seemed to be the case this year. Before the official opening of the Retrovirus Conference, American activists organized a cure workshop. Among the 60 or so participants there were even some high-profile researchers and FDA employees underlining the quality of this workshop.

Dan Kuritzkes started with an overview of the work of the Aids Clinical Trials Group (ACTG) in the field of the cure, this being meanwhile the focus of the work of this study network. He emphasized the importance of asking the right questions first:

Can the residual virus production below the limit of detection been suppressed by intensification?

is there a practically relevant decay of latent reservoirs?

can strategies that activate latent cells further lower the viral load?

can a combined approach lead to control of viral replication without drugs (functional cure)?

Apart from that, we must first find out how to approach the reservoirs methodically and what to measure.
Then he gave an overview of current ACTG trials:

A5276s: Patients with ongoing viral replication inspite of therapy (70 patients recruited, further 40 patients identified as suitable)

Planned study to look at the decay of reservoirs in different patient groups (acute / chronic infected, elite controller, blipper, patients failing therapy / resuppressing)

Interventional studies:

A5248/9s: Viral dynamics with TDF/FTC/RAL (cf. Abstract 672). Since viral decay is much faster with Raltegravir-containing regimens, the pecularities of this combination should be looked at.

A5281: studying a multi-antigen/cytokine/DNA-vaccine (already recruiting, so far no tolerability issues)

A5286: Study looking at Rifaximin (an oral broad-band antibiotic that is not being resorbed and therefore active only in the gut). Can the microbial translocation and the resulting systemic inflammation be mitigated? Also the influence on the reservoirs is to be studied.

A52301: Anti-PD1-Antibody: Quiescent cells harboring latent HIV can be forced out of latency with antibodies against the PD1-receptor and start producing virus. This study is still in concept phase.

A52308: ART for elite controllers

PR652: Effect of romidepsin (a cancer drug developed by Celgene that also acts as HDAC-inhibitor that can activate latent cells but isn‘t mutagenic in the Ames test as other drugs of this class) on the reservoirs: concept

Finally, Kuritzkes came back to the questions that need to be addressed:

What is the goal?
sterilizing cure?
functional cure, i.e. control of the virus by the immune system?
reduction / elimination of the remaining viral load?
reduction / elimination of viral reservoirs in the various compartments?

Which endpoints should be looked at?
proof of biological activity on the target or the selected mechanism?
proviral DNA in PBMSs?
proviral DNA in cells of the compartments (which?)?
cell-/tissue associated viral RNA?
no viremia during analytical treatment interruption (ATI)

Here he pointed out the (dis-)advantages of an ATI:

Pros:
-Best test for functional cure
-quantitative and qualitative analysis possible:
            -Rebound of viral load (or lack of)          
time to rebound
time to new setpoint
setpoint at a new (lower) level than before therapy
Cons:
Risk of inflammatory syndrome like during primary infection
risk for OI, CV-events, death (like in SMART-study)
increased transmission risk

We also have to think which patients are best being studied:

patients with successful ART (i.e. undetectable VL)
first vs. following regimes?
highly therapy experienced patients?
patients with well preserved immune function (high CD4-counts) or with advanced disease?
Elite controller?
acutely infected patients?
patients in need of a bone marrow transplant?

Finally, we must not forget the risk-benefit-balance since all new therapies will have to compete with established ART which is generally well tolerated and harbors usually only minor risks.

After that, Romas Geleziunas, Director of Virology at Gilead Sciences gave an overview of his company‘s activities in this area.

Gilead is focussing on the activation of HIV-expression in latently infected cells.

There are several possibilities:
De-repress chromatin (HDAC-inhibitors)
activate transcription factors (NF-ƘB)
activate HIV mRNA Elongation (PTEF-b)
Other mechanisms, still to be found by Hight-throughput analysis (HTS)

Gilead has developed an automatic system that can measure the reversal of latency with high numbers of samples at the same time. Already several new drugs have been discovered that can wake cells from latency. One of these, GSI-002 has the advantage of not being mutagenic and not activating T-cells itself. Some other compounds they found have such unbelievable names as "Thapsigargin“ or "Tyrphostin A“.

Another possible mechanism to eliminate HIV uses the "toll-like-receptor 7“ (TLR7). This receptor binds single-strand RNA and leads to the production of type-1 interferons (IFN alpha/beta). GS-9620 is a TLR7-agonist that has been shown to lower RNA and viral antigen production in several animal models. In a next step they will look whether this drug can play a role in eliminating HIV-infected cells. The mechanism of HIV latency needs to be understood still more fully and new drugs need to be discovered that play a role in or can interfere with this process.

Dale Ando, working for Sangamo Biosciences, once more presented the method of his company to knock out the gene for the CCR5-receptor with sequence specific zinc finger nucleases. This leads to CD4-cells that are immune against infection with CCR5-tropic HIV. Unfortunately, they didn‘t show any new data. The procedure seemed to have worked exceptionally well in one patient, who is heterozygous for the Δ32-mutation, i.e. he has only one functional CCR5-gene per cell. Therefore, the next studies will recruit preferentally such patients. Furthermore, the procedure will be adapted for stem cells. The problem is, that the introduction of the zinc finger nuclease into the cells also triggers the differentiation process and the cells wouldn‘t be stem cells any more. Sometimes the devil is lurking in the details... Good news is, that the procedure has been automated, so more patients can be treated which facilitates larger studies.

Birger Sørensen from Bionor Pharma, a small Norwegian Biotech company with only 19 employees presented a very interesting approach: They changed certain highly conservated regions of the p24 protein in a way that makes it much more effectively recognized by human immune cells. For some time it was already known that infected people with a strong immune response against p24 have a slower disease progression. In order to further strengthen the vaccine response, they use their product called Vacc-4x together with GM-CSF (a growth factor for granulocytes/macrophages). Four primary and booster immunizations in 40 patients led to 92% showing a immune response with good tolerability. In another study patients were immunized while on ART, then there was a 10 week waiting period to allow the immune system to calm down and finally ART was stopped. In all patients the viral load rebounded upon interruption, but the vaccinated patients reached a new setpoint that was about 0,4 log lower (i.e. average viral load 20.000 cp/ml instead of 60.000). They hope to further lower the setpoint with more round of vaccination. In addition they try to improve the immune response with immune modulators like lenalidomide.
Another approach, called Vacc-C5 aims in a different direction: antibodies against the C5-region of gp120 cannot neutralize the virus, but they still lead to a slower disease progression. This is probably because the complex of C5 and gp41 bears some similiarity with the human HLA-complex and can hyperactivate the immune system. Antibodies can block this hyperactivation and so slow down the disease progression. In animal trials it was possible to produce antibodies with the Vacc-C5 vaccine. Trials in humans are planned. Both approaches together would make use of the cellular as well as the humoral arm of the immune system and such a combined approach could be an important step on the way to a cure. The main problem right now is money because studies are expensive and a small company like Bionor is heavily dependent on investors.

John Zaia from Beckmann Research Institute gave an overview over the state of stem cell research in the area of HIV. It was a stem cell transplant that led to the cure of the "Berlin patient" and brought cure research back on the scientific agenda of the HIV researcher. But it is still unknown which factors were important for this experiment to succeed. Some researchers think that the graft-vs.-host-reaction, which almost killed the patient, was crucial - in addition to the radiation and the intense chemotherapy. So far, there is no second "Berlin patient", probably because the combination of the right tissue antigens and the CCR5-Mutation is rather rare. That‘s why they try to introduce the required CCR5-mutation artifically in bone marrow cells of donors. Another possibility to get stem cells is cord blod from newborns. But again here is the problem of the rare occurence of a CCR5-Mutation so there are plans to found a blood bank of cord blood with CCR5-Mutation. Alltogether the field of stem cell therapy is still in it‘s infancy. In patients who don‘t need a stem cell transplant for medical reasons (i.e. lymphoma), the risks are still too high. This method has only a chance for broader use when there will be new developments making radiation and chemotherapy unnecessary.

Pablo Tebas gave an overview over the activities of his workgroup. Apart from collaboration with Sangamon in the field of zinc finger nuclease (see above), the group also tries to increase the CD8-mediated killing of HIV-infected cells by providing the CD8s with a new T-cell-receptor that can recognize HIV much better than it‘s natural counterpart. Clinical studies including 16 weeks of ATI and rectum biopsies are planned. And there is renewed interest in the long known antiviral activity of interferon alpha against HIV. In a study with HIV patients that had undetectable viral load, stopped therapy and used pegylated interferon alpha as monotherapy, the viral load could be kept below 400 cp/ml in 45%. At the same time, the number of integrated HIV genomes in the circulating CD4-cells went down. Interestingly, this effect was also seen in a group of patients receiving only half of the standard dose (90 µg instead of 180 µg interferon alpha per week) - with much better tolerability.

David Evans and Nelson Vergel, two of the activists who had organized the workshop, did a internet survey about the willingness of patients to participate in clinical studies that are not of immediate benefit to them but maybe even have some serious risks. They found among many other things, that unexpectedly many patients would consider participating in such studies for mainly altruistic reasons.

Steven Deeks provide additional insight in the mechanisms of viral persistence of HIV:

reservoir of long living CD4 positive Tcm (Central Memory cells) harboring transcriptionally inactive HIV genome (latently infected)
homeostatic proliferation of these cells (i.e. because these cells divide to make up for natural decay, the integrated HIV genome will also be distributed to the daughter cells and the number of latently infected cells therefore decreases very slowly)
low level („cryptic“) viral replication induced by environmental stimuli, e.g. interactions with HIV infected CD4-cells in tissue.
failure to develop or maintain an effective anti HIV immune response

Deeks described these mechanisms in further detail and also some ideas how to overcome them, e.g. antibodies against PD1 to reverse latency.

Keith Jerome and Hans-Peter Kiem were the last presenter and described their efforts to

establish an HIV-resistant immune system permanently in patients and to
eliminate existing HIV reservoirs.

For the first goal they also use zinc finger nucleases. The viral reservoirs will be attacked with different tools: One idea is to mark infected cells with siRNA-probes to make them visible for the immune system so that killer cells can get rid off the infected cells. Another method uses "homing endonucleases", special restriction enzymes from yeast. The enzyme Y2-Anil has been changed in a way to recognize HIV-specific areas in the genome and cut them. These cuts will be recognized by the cells repair system and the gaps will be filled with random nucleosides. This leads to "nonsense“ viral sequence that doesn‘t produce active virus anymore. This method has a big advantage against the Tre-recombinase that has been described some time ago. Y2-Anil recognizes longer, very conserved regions of HIV so that it could be effective against a broad range of different HIV types whereas Tre recombinase is limited to the LTR region of HIV (in fact the efficacy of Tre recombinase has been shown only against a very artificial laboratory strain of HIV and not the wild type virus).

All speakers of this exceptional workshop shared the view that we must not raise premature and unrealistic hopes in patients. First steps have been made but we need many more successes in analytics, basic science and translational research in the animal model as well as in patients before the cure will be within reach.

Siegfried Schwarze

Support PoWeR

Program For Wellness Restoration

Health News

Blog Archive

The Cure of HIV is Possible in Our Lifetime