Innovative HIV Gene Therapy Study Soon to Start Enrollment

http://www.thebodypro.com/content/70316/innovative-hiv-gene-therapy-study-soon-to-start-en.html

Groundbreaking Gene Therapy Study Gets The Go-Ahead By The FDA

Calimmune, a small biotechnology company, is  giving people a low dose chemo agent (as conditioning) and then infusing them with stem cells  that have been modified to inhibit the CCR5 receptor and to contain their own built-in HIV fusion inhibitor peptide, thereby blocking two sites that are essential for HIV infection.  

The study is enrolling only for HIV+ people who have an R5 virus and who are not taking HIV medications due to their own choice (side effects, etc) for at least 6 weeks. Over 500 CD4 cells required.  Very promising approach  by Calimmune!

An Adaptive Phase I/II Study of the Safety of CD4+ T Lymphocytes and CD34+ Hematopoietic Stem/Progenitor Cells Transduced With LVsh5/C46, a Dual Anti-HIV Gene Transfer Construct, With and Without Conditioning With Busulfan in HIV-1 Infected Adults Previously Exposed to ART

http://www.clinicaltrials.gov/ct2

This is the Los Angeles investigator. San Francisco also has a site but it has been fully enrolled

http://www.uclahealth.org/body.cfm?id=479&action=detail&ref=7773

Novel Cell and Gene Therapies for HIV

Although the development of cell-based and gene transfer therapies has been slow, progress in a number of areas is evident. Advances in the fields of gene-targeting strategies, T-cell-based approaches, and HSCs have been encouraging, and a series of ongoing and planned trials to establish proof of concept for strategies that could lead to successful cell and gene therapies for HIV are under way. The eventual goal of these studies is to eliminate latent viral reservoirs and the need for lifelong antiretroviral therapy.




http://perspectivesinmedicine.org/content/2/10/a007179.full

Immune Cells Modified by Gene Therapy Survive After a Decade in HIV+ People

What an amazing study!

They have followed HIV+ people that have had T cells modified by genetic engineering and given by transfusion once during the past 11 years of study . 41 of the 43 people were still healthy 11 years later.  Their modified T cells could still be found in their bodies.

Modified T cells were detected in 98% of samples tested for at least 11 years after infusion at frequencies that exceeded average T cell levels after most vaccine approaches studied to date. Their inserted  transgene retained expression and function to resist HIV infection. The modified (CD4z )T cells had stable levels of incorporation into the body's tissues, with decay half-lives that exceeded 16 years, in marked contrast to previous trials testing engineered T cell trials.

The sample size was small but this study provides the first data of long term safety of this approach. The HIV cure research field is moving fast!


http://www.businessweek.com/news/2012-05-02/gene-therapy-safe-in-decade-long-hiv-study-that-may-widen-use

ABSTRACT
www.ScienceTranslationalMedicine.org 2 May 2012 Vol 4 Issue 132

Decade-Long Safety and Function of Retroviral-Modified
Chimeric Antigen Receptor T Cells

John Scholler,1* Troy L. Brady,2* Gwendolyn Binder-Scholl,1 Wei-Ting Hwang,3 Gabriela Plesa,1 Kristen M. Hege,4 Ashley N. Vogel,1 Michael Kalos,1 James L. Riley,2 Steven G. Deeks,5 Ronald T. Mitsuyasu,6 Wendy B. Bernstein,7 Naomi E. Aronson,7,8 Bruce L. Levine,1 Frederic D. Bushman,2† Carl H. June1†

The success of adoptive T cell gene transfer for treatment of cancer and HIV is predicated on generating a response that is both durable and safe. We report long-term results from three clinical trials to evaluate gammaretroviral vector–engineered T cells for HIV. The vector encoded a chimeric antigen receptor (CAR) composed of CD4 linked to the CD3z signaling  chain (CD4z). CAR T
cells were detected in 98% of samples tested for at least 11 years after infusion at frequencies that exceeded average T cell levels after most vaccine approaches. The CD4z transgene retained expression and function. There was no evidence of vector-induced immortalization of cells; integration site distributions showed no evidence of persistent clonal expansion or enrichment for integration sites near genes implicated in growth control or transformation. The CD4z T cells had stable levels of engraftment, with decay half-lives that exceeded 16 years, in marked contrast to previous trials testing engineered T cells. These findings indicate that host immunosuppression before T cell transfer is not required to achieve long-term persistence of gene-modified T cells.
Further, our results emphasize the safety of T cells modified by retroviral gene transfer in clinical application, as measured  in >500 patient-years of follow-up. Thus, previous safety issues with integrating viral vectors are hematopoietic stem cell or transgene intrinsic, and not a general feature of retroviral vectors. Engineered T cells are a promising form of synthetic biology for long-term delivery of protein-based therapeutics. These results provide a framework to guide the therapy of a wide spectrum of human diseases.
These results provide a framework to guide the therapy of a wide spectrum of human diseases.

Author affiliations:

1Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104–6076, USA. 2Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104–6076, USA. 3Department of Biostatistics and Epidemiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104–6076, USA. 4Celgene Corporation, 1500 Owens Street, Suite 600, San Francisco, CA 94158, USA. 5Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA. 6Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90035, USA. 7Walter Reed National Military Medical Center, Bethesda, MD 20889, USA. 8Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.

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

Report of This Weekend's HIV Cure Workshop in Seattle

A couple of months ago a rag tag group of activist--including Project Inform (represented by myself), the Treatment Action Group (TAG) and the AIDS Treatment Activists Coalition (ATAC)--reached out to some of the world's leading HIV researchers and companies working on HIV cure research and asked them to spend an entire day with us talking about potential barriers to moving such research forward at the fastest possible pace.

We also asked them to tell us the things that people like us--ordinary people with HIV and their allies--could do to boost research momentum and progress. At first, we were worried they might not be willing to add yet another day to an already long conference, the Conference on Retroviruses and Opportunistic Infections (CROI), taking place the following week. Would they see activists as worthy allies? Would they consider our goal--to map out an advocacy agenda to increase and hasten HIV cure research--something worth spending their time on?

More here: Seattle HIV Cure Meeting Report

HIV Reservoirs and Cure Research Lecture at CROI 2012

The first presentation in this link shows Dr John Mellors speaking at the Conference of Retroviruses and Opportunistic Infections in Seattle on March  5, 2012.  He did a great job at an overview of where we are in HIV Cure Research.

HIV Reservoirs and Cure Research Lecture

CD4 cell manipulation and reinfusion...will they make a difference in long term survival?

Very cool article on Matt's CD4 cell manipulation and reinfusion

Will this be a solution for people whose CD4 cells have remained low even after years of undectectable viral load? Are these "HIV resistant" CD4 cells functional in the long run? Well, Matt thinks his health has improved and he no longer has sinus infections like he used to before he joined the study.  We may soon need all of you to support this new concept, so be ready!

http://www.hivandhepatitis.com/hiv-treatment/hiv-cure/3275-gambling-for-a-cure-for-hiv?ic=700100

Interview with Man Who Got Cured of HIV

This link has a video of an interview with Tim Brown, the man who got cured of HIV (who I refer to as the "Berlin Patient"  in my article below).

http://feedroom.businessweek.com/?fr_story=4a74617791423dc8652dd78d84817c27ba4045aa


From TheBodypro.com

Zinc Fingers and Gene Therapies for HIV: Mimicking the Cured Berlin Patient?

By Nelson Vergel

March 2, 2011

Jay Lalezari, M.D., from the University of California-San Francisco presented first-of-its-kind study data on the use of zinc finger nucleases (ZFNs) to artificially disrupt the CCR5 receptor on the surface of CD4 cells, which HIV uses to infect its human host. The study is an attempt to determine if genetically modifying a patient's own CD4 cells could result in the augmenting of the patient's immune system with lasting, HIV-resistant cells.

Some HIV-infected patients who have an undetectable viral load while taking HIV medications continue to have low CD4+ cell counts. Lalezari et al decided to perform their proof-of-concept study on six of these patients: Each was on HIV antiretrovirals, had an undetectable HIV viral load, had a CD4+ cell count between 200 and 500, and had been HIV infected for more than 20 years. The patients were enrolled in one of two cohorts: in one, 10 billion total cells were modified; in the other, 20 billion. The process involved autologous (i.e., derived from the patient) R5-disrupted T cells that were expanded and modified with ZFNs outside the patients' bodies and then infused into the patients. The patients were followed weekly for one month and then monthly for 11 months post-infusion; blood and rectal mucosa samples were taken.

This novel study construction is the result of a history of groundbreaking findings. CCR5 has long been of interest to HIV researchers because many people who are resistant to HIV infection have a mutation in their CCR5 gene: the delta32 mutation. A minority of people of northern European descent (1% to 2.5%) have this mutation in the CCR5 receptor. After studying these patients, the oral CCR5 inhibitor drug maraviroc (MVC, Selzentry, Celsentri) was developed and ultimately approved in the U.S. in 2007. Fears that blocking the CCR5 receptor would lead to more rapid HIV disease progression or the emergence of other health problems have slowly dissipated since the drug was first given to humans in studies. (That said, there are some known adverse effects of CCR5 receptor blocking, including increased susceptibility to West Nile virus.)

As maraviroc was being developed, companies such as Sangamo BioSciences, Inc., were already trying to block the CCR5 receptor in a more permanent way: by using zinc finger nucleases, which act like scissors that cut the gene that codes for that receptor. But in the past, studies trying to modify CD4 cells in this manner have shown limited persistence of these cells after infusion in patients.
At the same time, some clinicians around the world were also trying to think outside the box on how to block HIV entry into CD4 cells. One such progressive thinker was Gero Hütter, M.D., from the Charité-Universitätsmedizin in Berlin. He had an HIV-infected patient with leukemia; he decided to try to treat both the patient's leukemia and HIV via a stem cell transplant using a donor with the delta32 mutation.

Hütter (and his patient) was lucky to find such a donor. The transplant -- which treats leukemia by essentially rebooting the body's immune system and creating new white blood cells -- also had the benefit of wiping out the HIV infection in the patient. The results of this extraordinary case were presented at CROI 2008 without receiving much excitement from the medical community.

It wasn't until almost two years later -- when it was found that the "Berlin patient" was still free of HIV not only in the blood, but in other compartments as well -- that excitement grew. Now, four years later, the patient remains HIV-free, which suggests he is cured of the disease. This has given companies such as Sangamo even more motivation to pursue a potential functional cure via disruption of the CCR5 receptor.

The data presented by Lalezari about Sangamo's ZFN approach showed several things:

1. The infusion was safe and well tolerated.
2. CD4+ cell count increases were seen in five of the six patients. The patient who did not respond had pre-existing antibodies to the adenovirus vector used to deliver the ZFN into the CD4 cell, so his body destroyed the vector, rendering the ZFN inactive. About 50% of the human population has those same antibodies, so a different vector may be used in future studies.
3. The percentage of CCR5 disruption in the peripheral blood of the five responders was 6%, 3%, 1%, 2%, and 2% (respectively) at day 14 and persisted for the duration of the follow-up. CD4+ cell counts increased in all patients at day 14 (from an average of 35 to 1038 cells/mm³) and were sustained at all time points (with mean increases of 208, 86, 233, 911, 210 cells/mm³, respectively). CCR5-disrupted cells were detected in the rectal mucosa of all patients at all assessed time points, with levels of CCR5 disruption approximating that of peripheral blood when normalized for CD4 cells within each compartment.
4. Three of the five responders had normalization of the CD4/CD8 ratio, which is a hallmark of the health of the immune system.
5. There was a good uptake (grafting) of the modified CD4 cells into the blood of the five responders. In fact, by day 14 these patients had three times the quantity of cells that had been infused, showing that there was a growth of modified cells in their bodies. By day 90, the levels of persistent engraftment had become 6- to 40-fold greater than previously reported. After three months, 6% to 7% of the CD4 cells in the circulating blood had evidence of gene modification, which is over 10-fold higher than achieved by any previous T-cell modification therapy in HIV.
6. Homing of these cells to the gut mucosa was observed in all patients tested, with CCR5 disruption levels similar to that of peripheral blood, suggesting these cells traffic normally. This is important since gut mucosa is the interface between the immune system and HIV.
7. As I noted above, there were two cohorts in dosing: 10 and 20 billion cells. There seemed not to be a response difference between those two cell doses. Cells grafted and expanded during the first two weeks.

This exciting study opens the door to new possibilities, but many questions remain unanswered:

1. What will happen long-term with the newly engrafted CD4 cells? Will they provide a survival or comorbidity benefit in these patients? (Note: Patients in this study will be followed for life.)
2. Will this approach help control HIV replication in patients who stop antiretrovirals after long-term HIV suppression? How can we ethically ask patients to enroll in studies that require a structured treatment interruption? Will institutional review boards be willing to approve these kinds of studies in the future?
3. Do people do better with more than one infusion? What is the best number of cells to ensure optimum immunological response?
4. Will this approach help control HIV replication in treatment-naive patients who have a detectable viral load and who are not taking HIV antiretrovirals? Will these cells still have a survival advantage when challenged with untreated HIV? (Note: Lalezari is currently enrolling a 14-patient study in San Francisco that will attempt to answer these questions.)
5. Will these gene-modified cells have a survival and activity advantage against HIV across the board? Will HIV viral load be controlled well enough for people to stop using antiretrovirals -- or, as stated in the question above, allow them to avoid antiretrovirals entirely?
6. What will the cost of this procedure be?
7. What happens to those with pre-exposure to the adenovirus vector who cannot respond to this type of zinc finger nuclease delivery method?

We should be careful not to overreach with these data. Many people are throwing the "cure" word around when talking about this study, but this is just a very preliminary effort to start answering important questions toward that goal.
At a CROI 2011 press conference, Lalezari and other researchers involved in zinc finger nuclease and HIV gene therapy research discussed their findings and the broader implications of those findings. Click here to read that transcript.

HIV Gene Therapy Data Update

HIV Gene Therapy Data Update

HIV Gene Therapy Data Reported This Month

Sangamo Says Experimental Therapy Kept HIV Level Low

By Rob Waters - January 19, 2010 16:05 EST

Jan. 19 (Bloomberg) -- Sangamo BioSciences Inc., a company developing gene-based therapies for AIDS and other conditions, said an experimental treatment kept down levels of HIV, the virus that causes AIDS, in the first patient tested in a study.

The patient interrupted his antiviral medications after infection-fighting cells that are targets of the virus were treated with the Sangamo product. His viral levels didn’t rise for six weeks, two weeks to four weeks later than typical patients who halt medication, Richmond, California-based Sangamo said today in a statement.

The therapy uses an engineered protein called a zinc finger nuclease to try and neutralize a receptor called CCR5 that HIV uses to enter and infect immune cells. This approach aims to replicate the immunity to HIV infection enjoyed by 1 percent to 2 percent of people whose own CCR5 genes are mutated.

The zinc finger technology “provides a totally new approach to HIV/AIDS with the aim of providing a reservoir of functional T-cells that are resistant to infection by HIV and available to fight opportunistic infections,” Dale Ando, Sangamo’s chief medical officer, said in the statement. “These data are an early indication that this may be possible.”

Sangamo's Bet Against AIDS: Gene Therapy - "The bottom line: Sangamo BioSciences is testing a gene therapy for AIDS inspired by a cured patient. The first results come this month."

Inspired by one man's cure, the biotech tweaks patients' genes

"preliminary data will be reported on Feb. 27 at a medical conference in Boston. Moussatos says that if the data are strong, Sangamo may attract partnerships with larger drugmakers that it will need to help finance larger trials."

Video Interview with patient:

http://feedroom.businessweek.com/?fr_story=4a74617791423dc8652dd78d84817c27ba4045aa

Feb 10, 2011, By Rob Waters

www.businessweek.com

Timothy Brown may be the only person cured of AIDS. Brown, who lives in San Francisco, in 2007 received a stem-cell transplant in Berlin that transferred genetic material to him from one of the up to 2 percent of humans with a natural immunity to the disease. He has been off treatment since then, and no traces of the AIDS virus have been found in his body, says his hematologist, Gero Hütter, now with the German Red Cross in Mannheim. His case has encouraged tiny Sangamo BioSciences (SGMO) to develop a new form of gene therapy that could offer others the same result.

While there's no guarantee Brown, 44, will remain virus-free, his case has spurred scientists to try to duplicate the result without a dangerous stem-cell transplant. Sangamo, a Richmond (Calif.) biotechnology company, will report data late this month on a gene therapy that's likely to be less risky. If the results are a success, and the method is eventually approved, it may generate $750 million a year in U.S. sales, says Liana Moussatos, a biotech analyst at Wedbush Securities. "It's high-risk, but definitely high-reward," she says. "If this is a cure for HIV that prevents or reduces the lifelong need for drugs, that's a huge accomplishment."

Sangamo's stock has more than doubled since July 6, when the company, with no products on the market, reported success of its gene therapy approach in mice in the journal Nature Biotechnology. One reason for the enthusiasm: The therapy, using a new technology that acts like biological scissors to cut into genes at precise points, may also treat other diseases, such as hemophilia, Parkinson's, and neuropathy, the nerve damage caused by diabetes, says Sangamo Chief Executive Officer Edward Lanphier. An approved treatment for neuropathy alone, which has no cure, may generate $6 billion a year, Moussatos says.

Sangamo is conducting two studies of its HIV therapy in 21 people. Both are in the first stage of testing usually required to win U.S. regulatory approval. Its preliminary data will be reported on Feb. 27 at a medical conference in Boston. Moussatos says that if the data are strong, Sangamo may attract partnerships with larger drugmakers that it will need to help finance larger trials.

There are 1.1 million Americans living with the AIDS-causing HIV virus, and 34 million are infected worldwide, according to the U.S. Centers for Disease Control and Prevention. Antiviral drugs, led by Atripla and Truvada, made by Gilead Sciences (GILD) and Bristol-Myers Squibb's (BMY) Reyataz, generated $15.1 billion in worldwide sales last year, according to industry researcher IMS Health.

AIDS first emerged in 1981 and, in the early years, killed most of those infected within a year of diagnosis. In 1996 doctors began combining three different families of drugs to overcome HIV's ability to become resistant. That extended lives of patients in North America and Europe by at least 13 years on average, according to a 2008 study. Still, the drugs aren't a cure, since the virus rebounds when their use stops. They are taken daily, often cause nausea, and can trigger kidney damage. They also need to be regularly adjusted as the virus mutates, gaining resistance in the body.

In the Sangamo process, doctors draw patients' blood and remove infection-fighting white blood cells. They are then modified using naturally occurring proteins called zinc fingers that cut into patients' DNA at selected points. Chopping the DNA in the middle of a gene called CCR5 eliminates a receptor that HIV uses to gain entry to cells. The modified cells are then returned to the patient through an infusion.

"This approach shows the most promise of any that I know of," says Jay A. Levy, a researcher at the University of California in San Francisco who helped identify HIV as the source of AIDS in 1984. "It's a terrific way of looking for a long-term functional cure for the virus."

One person who hopes it will prove effective is Matt Sharp, 54, an AIDS educator who was diagnosed in 1988 and today takes a daily regimen of three antivirals. He learned about the Sangamo trial a year ago and enrolled. Since last summer, when Sharp received an infusion of his own gene-modified T-cells, blood cells that help the immune system fight infection, the number of those cells has doubled, he says. "I'm just hoping I could get an infusion once a year that would keep HIV under control and I won't have to deal with the effects of taking medication."

CCR5 isn't a new target. The gene pathway was first noticed in the mid-1990s by scientists studying people immune to HIV infection. In these people, including the donor who contributed stem cells to Brown, the CCR5 gene is mutated and inactive, keeping the virus from gaining a foothold in the immune system. For most HIV patients, however, a stem-cell transplant is impractical and risky. It requires finding a donor with the CCR5 mutation and whose tissues and blood match the patient's—and carries about a 30 percent risk of death, says Levy.

That's too high a risk for most AIDS patients who have access to proven antiviral medicines. Brown, previously known in medical circles only as "the Berlin patient," was willing to take the chance because he also had developed a potentially fatal case of leukemia—a blood cancer that can also be treated by stem-cell transplants. When chemotherapy stopped controlling his leukemia, Brown and his doctors decided to find a donor with genetic characteristics that would allow treatment of both conditions simultaneously. Brown underwent two stem-cell transplants. Afterward he developed neurological problems and other side effects and spent a year in the hospital, at some points near death. He eventually recovered and was released in early 2009.

"If I hadn't survived, I kind of doubt that the work towards a cure would have gone this far," Brown says. Now he hopes scientists will be able to develop new therapies based on his treatment "so people can be cured of HIV without having to go through what I went through."

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Zinc Fingers Disrupts CCR5/HIV Entry; Sangamo and the University ...

Dec 28, 2009 ... Sangamo BioSciences, Inc. (Nasdaq: SGMO) announced today that its collaborators at the University of Pennsylvania have opened a Phase 1 ...www.natap.org/2009/newsUpdates/122909_01.htm

Sangamo BioSciences Initiates Phase 1 Trial of CCR5-ZFP ...

Feb 3, 2009 ... Sangamo BioSciences, Inc. (Nasdaq: SGMO) announced today that its collaborators at the University of Pennsylvania have opened a Phase 1 ...www.natap.org/2009/HIV/020409_01.htm

New Gene Therapy Zinc Fingers Research Published: 'doctors may someday control HIV virus using stem cells without using anti-retroviral drugs' ......'Human hematopoietic stem/progenitor cells modified by zinc-finger nucleases targeted to CCR5 control HIV-1 in vivo' in Nature Biotevhnology July 2 2010......

New Gene Therapy Zinc Fingers Research Published: 'doctors may ...

Jul 2, 2010 ... Human hematopoietic stem/progenitor cells modified by zinc-finger nucleases targeted to CCR5 control HIV-1 in vivo ...
www.natap.org/2010/HIV/070610_01.htm

Can HIV be cured with stem cell therapy? commentary

by SG Deeks - 2010 -Can HIV be cured with stem cell therapy? commentary. Steven G Deeks and Joseph M McCune. Nature Biotechnology July 2010 full text of study in mice:...www.natap.org/2010/HIV/081010_01.htm

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Sangamo BioSciences Initiates Phase 1 Trial of CCR5-ZFP Therapeutic to Treat HIV/AIDS

RICHMOND, Calif., Feb 03, 2009 -- Therapeutic Approach Provides HIV-Resistant Immune Cells

Sangamo BioSciences, Inc. (Nasdaq: SGMO) announced today that its collaborators at the University of Pennsylvania have opened a Phase 1 clinical trial to evaluate SB-728-T for the treatment of HIV/AIDS.

Based on Sangamo's zinc finger DNA-binding protein nuclease (ZFN) technology, SB-728-T has been shown in an animal model of HIV infection to lead to an increase in CD4+ T-cell counts, a reduction in viral load and expansion of CCR5-modified T-cells, suggesting resistance to HIV.

"This is the first time that we have had the ability to make a patient's T-cells permanently resistant to infection by CCR5-specific strains of HIV and we are very excited to begin a clinical trial of this novel ZFN-based therapy," said Carl June, M.D., Director of Translational Research at the Abramson Family Cancer Research Institute at the University of Pennsylvania School of Medicine. "The ability to protect immune cells from infection with HIV and the expansion of CCR5-modified T-cells has the potential to provide long-term control of both the virus itself and eventually the opportunistic infections characteristic of AIDS."

CCR5 is a co-receptor that enables HIV to enter and infect cells of the immune system. About ten years ago, it was observed that individuals carrying a natural mutation of their CCR5 gene, CCR5-delta32, were highly resistant to infection by HIV. These individuals, lacking a functional CCR5 (approximately 1-2% of the general population), are immunologically "normal". A variety of small molecule and antibody antagonists of CCR5 binding have been tested and developed as potential therapeutic agents for the treatment of HIV infection. In addition, there is a recent report of a patient who had both HIV infection and leukemia and received a bone marrow transplant from a donor carrying the CCR5 mutation. After the successful bone marrow transplant, HIV treatment was discontinued and the virus could not be found in the circulating blood several months after the procedure. Sangamo's ZFNs are designed to modify the DNA sequence encoding CCR5. This modification can occur directly in T-cells with only a brief exposure to the ZFNs. Once the modification is made to the T-cell's CCR5 gene it is permanently disrupted.

"Our ZFN approach is very well-validated by naturally occurring mutations in man and the recent bone marrow transplant report," commented Dale Ando, M.D., Sangamo's vice president of therapeutic development and chief medical officer. "However, allogeneic bone marrow transplantation (bone marrow taken from a different person) is not widely applicable as a therapeutic approach for HIV as it is a risky procedure requiring irradiation and ablation of the immune system and matched donors who also carry the CCR5-delta32 mutation are likely to be rare. Small molecule or antibody antagonists require the constant presence of a high concentration of drug in order to block therapeutically relevant numbers of the CCR5 protein.

In contrast, we believe that our ZFN technology provides an approach that circumvents the dosing and potential toxicity issues of a systemic therapy and provides a simpler approach than a transplant. We specifically modify the patient's own CD4+ T-cells, the principal target of HIV infection, with a one-time exposure of the cells to CCR5-specific ZFNs. This generates a population of T-cells that lack the CCR5 receptor, are resistant to HIV and can be infused back into the patient to provide a reservoir of HIV-resistant functional immune cells and, more importantly, may expand and provide an HIV immune response."

"Our ZFP technology functions at the DNA level and, as this application demonstrates, enables us to address highly validated therapeutic targets that have proven difficult to drug at the protein and RNA levels," commented Edward Lanphier, Sangamo's president and CEO. "ZFPs can be engineered to regulate or modify any gene, in any cell type, which provides numerous opportunities for its therapeutic applications. This trial is another important step in establishing our ZFP technology as a major new therapeutic product development platform."

About the SB-728-T Clinical Trial

The study is an open-label Phase 1 clinical trial of the safety and tolerability of a single infusion of autologous (a patient's own) CD4+ T cells genetically modified at the CCR5 gene by CCR5-specific ZFNs (SB-728-T). A total of twelve subjects with HIV will be enrolled in this trial in two treatment cohorts. The first cohort to be treated comprises six subjects who have failed two or more HAART (Highly Active Antiretroviral Therapy) regimen. The first three subjects in this cohort will be treated sequentially and monitored for the first 21-days post treatment before an additional subject is treated. After this period of evaluation and monitoring has passed successfully, the next three subjects will be treated. The second cohort comprises six subjects who are responsive to their current therapy regimen who will be treated with CCR5-modified T-cells and undergo a structured therapy interruption (STI) or therapy "break". The primary objective of the study is to evaluate the safety and tolerability of SB-728-T. In addition to safety monitoring, data will be collected on the expansion and persistence of ZFN-modified cells, CD4+ cell counts and viral load. Individuals interested in participating in this trial should visit http://www.clinicaltrials.gov/ or contact Larisa Zifchak, R.N. at 215-349-8091 (larisa.zifchak@uphs.upenn.edu), Joe Quinn at 215-349-8091 (joseph.quinn@uphs.upenn.edu) or Pablo Tebas, M.D. at 215-349-8091.

Preclinical Data

Preclinical data on SB-728-T were published in the journal Nature Biotechnology (Perez E. E. et al., Nat Biotechnol. 2008 Jul; 26(7):808-16.) and presented at the joint meeting of the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) and the Infectious Diseases Society of America (IDSA) in Washington, DC in October 2008. The results demonstrate that a one-time exposure to CCR5-specific ZFNs resulted in the generation of an HIV-resistant population of human primary T-cells by the permanent genetic modification of the CCR5 gene. These ZFN-modified CD4 T-cells expanded stably in HIV-infected cultures for several weeks and appeared to behave identically to untreated T-cells except that they were resistant to infection by HIV. ZFN treated primary CD4 T-cells and transformed CD4 cell lines resisted infection with R5-tropic HIV (virus that uses the CCR5 co-receptor to enter cells), resulting in enrichment of ZFN-generated CCR5-disrupted cells in the population upon long-term exposure to virus (>50 days). Importantly, in the presence of HIV, ZFN-modified CD4 T-cells also preferentially expanded in a mouse model. The modified cells were infused into mice that lack a normal immune system and thus do not reject human cells. After 33 days, the mice were sacrificed and analyzed for the presence of ZFN-modified cells. Researchers determined that ZFN-modified cells engrafted normally in the mouse and that the proportion of modified cells present at the end of the experiment was greater than two to three fold higher in mice in the presence of HIV infection (p=0.008). In additional experiments it was determined that 50 days after infection, mice given the ZFN-modified cells had increased numbers of CD4 cells and a statistically significant reduction in viral load in their peripheral blood (P<0.001) compared to mice given control cells. These data suggest that, in the presence of HIV, the ZFN-modified cells have a selective advantage allowing them to evade infection and destruction leaving them able fight opportunistic infections and HIV itself.

About HIV/AIDS and CCR5

HIV stands for Human Immunodeficiency Virus. HIV infection kills or impairs cells of the immune system progressively destroying the body's ability to fight infections and certain cancers resulting in AIDS (Acquired Immune Deficiency Syndrome). Individuals diagnosed with AIDS are susceptible to life-threatening diseases called opportunistic infections, which are caused by microbes that usually do not cause illness in healthy individuals. According to UNAIDS/WHO, over 2.7 million people were infected with HIV in 2007. There are now over 33 million people living with HIV and AIDS worldwide.

CCR5 is the chemokine receptor that HIV uses as a co-receptor to gain entry into immune cells. CCR5 is perhaps the most important of the known co-receptors for HIV, since the most commonly transmitted strains of HIV are strains that bind to CCR5 -- so-called "R5" strains. A small fraction of the population carries a mutation in their CCR5 gene, called the delta32 mutation. This mutated version of the gene produces malformed CCR5 proteins, which cannot be used by HIV as a co-receptor. Individuals that have two copies of this mutant form of CCR5 (delta32) are resistant to infection by R5 HIV strains.

Dr. June is not affiliated with Sangamo BioSciences in any capacity beyond his role as a clinical collaborator on this project.