POZ Community Forums
Meds, Mind, Body & Benefits => Research News & Studies => Topic started by: John2038 on July 20, 2011, 05:02:49 pm
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Functional Cure in Non-Human Primates Achieved With Simian Version of VIRxSYS' HIV Vaccine VRX1273
Vaccine Uses Modified HIV Lentivirus Vector; HIV Virus "Very Low to Undetectable" in Reservoirs
ROME and GAITHERSBURG, MD--(Marketwire - Jul 18, 2011) - Researchers from VIRxSYS Corporation, the Gaithersburg, Maryland-based biotechnology company, today presented data indicating that a simian version of its HIV vaccine VRX1273 achieved a functional cure in a subset of rhesus macaques that had been challenged with a high dose of simian immunodeficiency virus (SIV). At 18 months after the SIVmac251 infection, VIRxSYS researchers report that some of the vaccinated animals displayed viral loads below levels of detection in blood plasma, blood cells, and cells residing in tissues defined as "reservoirs."
http://www.marketwire.com/press-release/functional-cure-non-human-primates-achieved-with-simian-version-virxsys-hiv-vaccine-1539045.htm
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So let me get this right: are they going to infect people with 'gutted' HIV so that the living HIV won't be able to infect the cells anymore?
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So let me get this right: are they going to infect people with 'gutted' HIV so that the living HIV won't be able to infect the cells anymore?
Yeah, So?
It always pleases me when we are able to cure monkey's of their aids!!
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This is good.
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the great thing is that they haven't in fact demonstrated anything. this stuff was proven on animals and on the simian version of the virus. i mean in terms of efficacy and safety it tells nothing. all this must be confirmed in human clinical trials and this press release serves only to find investments for starting trials. it has a long way to go and a high failure risk. the entusiasm in the article is overstated at the least.
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the great thing is that they haven't in fact demonstrated anything. this stuff was proven on animals and on the simian version of the virus. i mean in terms of efficacy and safety it tells nothing. all this must be confirmed in human clinical trials and this press release serves only to find investments for starting trials. it has a long way to go and a high failure risk. the entusiasm in the article is overstated at the least.
Is there Universal health care in Italy? Because if there is, you have nothing to worry about, even if a cure is never found.
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Inch, what does that have to do with the cost of tea in china?
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Inch, what does that have to do with the cost of tea in china?
I don't think you've been on here long enough to know xman's posting history. He believes a cure will never be found or if it is it will be a very long time. He may be right or he may be wrong but the fact is that the vast majority of people diagnosed nowadays will fare very well as long as they have access to health care and ARV meds.
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I don't think you've been on here long enough to know xman's posting history. He believes a cure will never be found or if it is it will be a very long time. He may be right or he may be wrong but the fact is that the vast majority of people diagnosed nowadays will fare very well as long as they have access to health care and ARV meds.
inch, if you read carefully my last interventions you will notice that i'm now much more optimistic about a cure in the next decade than before. i started the thread of bob frascino changing his positions on the issue and made other considerations. however to reach the goal of a cure in a reasonable timeframe i prefer to consider those drugs that are advanced testing phases. this drug is not even in human trials and all the hype about it is quite difficult to understand,at least for me. i put my hopes in candidates that are actually tested in humans and not in something that might reach phase 1 in a couple of years. also if you look on the site of virxsys they are still searching for financial backup to continue trials for their other candidate, vrx496 which is on ice since last year.
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I see.
I think we can all agree that even though these specific candidates may not be "the one" they all add up to more knowledge about the virus which in turn will lead to further gains. It is a bit much to get your hopes up about something that was tested in 5 monkeys, but its progress, and progress is good.
AND there is nothing wrong with having HOPE
Keep hope alive as Jessie Jackson would say!!
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I see.
I think we can all agree that even though these specific candidates may not be "the one" they all add up to more knowledge about the virus which in turn will lead to further gains. It is a bit much to get your hopes up about something that was tested in 5 monkeys, but its progress, and progress is good.
AND there is nothing wrong with having HOPE
Keep hope alive as Jessie Jackson would say!!
I dunno a full functional cure in 5 test subjects is pretty damn good news. Unfortunately it's SIV but as long as it works on the same mechanism in HIV this should be music to all of our ears. We'll wait and see like we always do, but optimism survives all.
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http://www.aidsmeds.com/articles/hiv_virxsys_vaccine_2636_20875.shtml (http://www.aidsmeds.com/articles/hiv_virxsys_vaccine_2636_20875.shtml)
I dunno a full functional cure in 5 test subjects is pretty damn good news. Unfortunately it's SIV but as long as it works on the same mechanism in HIV this should be music to all of our ears. We'll wait and see like we always do, but optimism survives all.
Unfortunately, it wasn't even in all five macaques -- only two. And while average survival appeared slightly better among the vaccinated monkeys that died, compared with unvaccinated macaques, the numbers were all over the place.
And why two of the monkeys appeared to do very well, where three other vaccinated monkeys appeared to have the same SIV viral loads, CD4 counts, etc. as the unvaccinated macaques in the study is important to know.
Still, I think the data are interesting... but let's also keep in mind that this was a vaccine, administered prior to infection, that led to (possible) functional cures in two of five immunized animals. Will any of this be possible using the human version of the vaccine, not only pre-infection but when used therapeutically in those living with the infection? Possibly, but nothing in these data points to a Eureka moment.
Tim
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video
http://www.youtube.com/watch?v=P9x00NnJgpI
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HIV/AIDS Key Opinion Leaders’ Feedback on VRX1273
VIRxSYS has presented its ongoing findings to scientists, HIV clinicians and Key Opinion Leaders (KOLs) from around the world, including those at the NIH, at conferences such as CROI (Conference on Retroviruses and Opportunistic Infection) in San Francisco in February 2010, the Vienna International AIDS Conference in August 2010, the AIDS Vaccine Conference in Atlanta in September 2010, the 2010 American Public Health Association Meeting in Denver, the HIV DART in Los Cabos, Mexico in December 2010, and to the Company’s globally renowned HIV Medical Advisory Board. The Company has received extremely favorable feedback on the data presented. For example, Dr. Joep Lange, the head of the Amsterdam Institute for Global Health and Development, Professor of Medicine at the Academic Medical Center, University of Amsterdam., President Emeritus of the International AIDS Society, and member of the VIRxSYS medical advisory board for HIV, stated, “Obviously, the HIV vaccine field has been hit with a number of disappointing trial results over the past several years. The results from this trial are very impressive and I believe could provide real excitement in the world of HIV vaccines.” Other HIV and vaccine experts expressed similar views and have encouraged VIRxSYS to move VRX1273 to human clinical trials as quickly as possible.
Next Steps for VRX1273
A Pre-IND meeting for VRX1273 was held with the Food and Drug Administration (FDA) in July 2010. The meeting outcome was very successful in that no major safety or clinical issues were identified at the time, which would prevent VIRxSYS from filing an IND application with the FDA.
VIRxSYS is now finalizing the remaining preclinical studies, as discussed with the FDA, for inclusion into the IND application, and is also preparing for its proposed Phase I human clinical trials for VRX1273.
Because of the devastating human impact that HIV/AIDS has had around the world, a significant number of attempts have been made to develop an HIV vaccine. The vast majority of the HIV vaccine trials to date have been for prophylactic HIV vaccines. While VRX1273 may one day have prophylactic application, VIRxSYS plans to move this product into clinical trials initially as a therapeutic vaccine. There have been numerous efforts to develop a therapeutic vaccine for HIV. VIRxSYS believes that while some of these programs have had some modest success, each of these programs/product candidates has helped move the field forward. However, none of them has resulted in compelling human clinical data so far.
VIRxSYS is very proud of the results to date with its vaccine candidate in monkey studies, including survival advantage and achieving undetectable viral load in some of the vaccinated animals, despite the highly virulent strain and dose of SIV used to challenge the monkeys. Because of this, VIRxSYS believes that VRX1273 has an outstanding opportunity to generate compelling data in humans where all other vaccine candidates have failed to date.
References
[1] UNAIDS report (http://www.unaids.org/documents/20101123_GlobalReport_em.pdf)
[2] Lemiale et al. An HIV-based lentiviral vector as HIV vaccine candidate: Immunogenic characterization. Vaccine 28(8) :1952-61, 2010.
[3] Lemiale & Korokhov. Lentiviral vectors for HIV disease prevention and treatment. Vaccine 27(25-26):3443-9, 2009 (Review)
[4] Asefa et al. Heterologous HIV-based lentiviral/adenoviral vectors immunizations result in enhanced HIV-specific immunity. Vaccine 28(20):3617-24, 2010.
[5] Lemiale F. HIV DART 2010, Los Cabos, Mexico. (http://www.informedhorizons.com/hivdart2010/_pdf/BrochureEmail_HIVDART2010.pdf)
Source (http://www.virxsys.com/pages/human-therapies/hiv-vaccine.php)
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http://www.aidsmeds.com/articles/hiv_virxsys_vaccine_2636_20875.shtml (http://www.aidsmeds.com/articles/hiv_virxsys_vaccine_2636_20875.shtml)
Unfortunately, it wasn't even in all five macaques -- only two. And while average survival appeared slightly better among the vaccinated monkeys that died, compared with unvaccinated macaques, the numbers were all over the place.
And why two of the monkeys appeared to do very well, where three other vaccinated monkeys appeared to have the same SIV viral loads, CD4 counts, etc. as the unvaccinated macaques in the study is important to know.
Still, I think the data are interesting... but let's also keep in mind that this was a vaccine, administered prior to infection, that led to (possible) functional cures in two of five immunized animals. Will any of this be possible using the human version of the vaccine, not only pre-infection but when used therapeutically in those living with the infection? Possibly, but nothing in these data points to a Eureka moment.
Tim
Thanks for clarifying. I don't read anything that directly relates to a cure, so all of my information is second hand. I trust that when and if an actual cure is found I'll know about through these forums or through a bombardment on television news channels.
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I trust that when and if an actual cure is found I'll know about through these forums or through a bombardment on television news channels.
Ironically, the biggest "cure" news we've seen to date -- Timothy Brown (aka, the Berlin Patient) -- started in the form of a 3' X 5' poster at the back of a cavernous hall at Hynes Convention Center in Boston during the Conference on Retroviruses and Opportunistic Infections in February 2008. AIDSmeds and a handful of other HIV publications noted its potential significance (http://www.aidsmeds.com/articles/hiv_aids_stemcell_2042_14199.shtml) and reported on it, but it went virtually unnoticed by the mainstream media. No press releases... No post- or pre-conference satellite symposia... no investor relations tactics. It wasn't until two years later, really, that the mainstream media woke to Brown's case.
Granted, a lot more folks are now keeping a keen eye open for reports such as this -- nobody even thought to look for cure-related poster presentations in 2008 -- but I honestly think it's the more obscure stuff at these conferences that generate the most intriguing science. I'm growing increasingly weary of the word "cure" in press releases -- we went from being afraid to even think the word to seeing it become exploited in record time -- but, when you consider the sum of the parts (some of which are discussed in this particular corner of the AIDSmeds Forums), it does seem as if we're moving in the right direction.
Tim
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No needs ta say, but I will say it, thank's for your great insights Tim!
Ironically, the biggest "cure" news we've seen to date
How would you compare the VRX1273 with the CMV and TAT based vaccines and the ZFN (CCR5 and CXCR4) ?
CMV
.. consisted of SIV (monkey HIV) components packaged inside an actively replicating vector consisting of the shell of the common CMV virus (Hansen). This vaccine, given to 26 monkeys, did not protect them from SIV infection but in 13 of the monkeys resulted in an infection characterised by a low viral load – which gradually turned into a situation in which there was no detectable virus in their bodies. This, if achieved in humans, would essentially be a ‘vaccine cure’. But we need to understand why only half of the monkeys responded and why – and actively replicating vaccines are potentially dangerous.
TAT/ENV
A vaccine consisting of the two HIV components tat and env inside another actively-replicating viral vector produced a similar effect, preserving the CD4 count and bringing the viral load down to undetectable in five monkeys, and down by a factor of 10,000 in the other three out of eight infected with a highly pathogenic variety of SHIV (Demberg). By comparison, monkeys receiving placebo maintained viral loads of a million and their CD4 count crashed to 10 cells/mm3 within two months. A phase 1 trial of a human version of this vaccine in 50 people is planned.
ZFN
..In all six participants the altered CD4 cells engrafted, or took up residence in the body, and proliferated in a manner similar to normal T-cells. Five of the six experienced significant, sustained increases in number of CD4 cells, averaging about 200 cells/mm^3, though gains varied widely across patients and over time. Five participants also experienced normalisation of the CD4 cell to CD8 cell ratio, which is typically reversed in people with HIV. After 90 days, up to 7% of peripheral blood CD4 cells showed the CCR5 deletion. Rectal tissue biopsies revealed that the altered CD4 cells were distributed to the gut lining like normal T-cells. The observed expansion of CD4 cells was on average three-fold greater than expected based on the number of infused cells, Lalezari noted. He acknowledged, however that the alteration procedure involved activating the cells, which may have contributed to their proliferation. The one participant who did not respond as well to the treatment had high levels of antibodies against the adenovirus vector, which may have made the CCR5 deletion procedure less effective. These results represent a proof of concept that further validates the Berlin patient findings, Lalezari said, but he cautioned that it is too early to talk about these results as a cure.
The next step will be to test the CCR5 removal procedure in HIV-positive people with replicatingvirus to see if re-infusion of altered CD4 cells reduces viral load and confers a clinical benefit. Researchers will look at treatment-naive individuals who have not yet started therapy, as well as some treatment-experienced "salvage" patients who are not responding current therapy. The hope, Lalezari said, is to provide a reservoir of cells that are resistant to HIV infection.
Sources
http://www.natap.org/2011/CROI/croi_28.htm
http://www.aidsmap.com/page/2016705
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All 4 vaccines seem to present promising results. Although it seems no one is quite sure just yet how to put a replicating virus as a vector that is safe in humans as yet. Seems there needs to be some safety issues worked out before the CMV and the other replicating virus vaccines even see human clinical trials!
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VIRxSYS Issued U.S. Patents for Its Lentiviral Vector and SMaRT RNA Platforms
http://www.marketwatch.com/story/virxsys-issued-us-patents-for-its-lentiviral-vector-and-smart-rna-platforms-2011-11-15
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Does anyone knows what happened to Virxsys? There is no news since november 15 2011 and they haven´t updated their homepage since.