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T-Cell vaccines

Posted: Mon May 21, 2007 2:20 am
by CureOrBust
I know its a tovaxin forum, and i know its had a higher published success rate, but why is it that there are so many people excited about a phase IIb treatment (Tovaxin) over a similar treatment (in my understanding of the theorys) already in Phase 3 [(T-Cell Vaccination (aka TCV-01-002) (Sheba Medical Center)] ??

If / Once it gets to market, I am sure they will improve its effectiveness to close to that of tovaxin.

Posted: Mon May 21, 2007 6:27 am
by IHaveMS-com
Hi Cure,
I know its a tovaxin forum, and i know its had a higher published success rate, but why is it that there are so many people excited about a phase IIb treatment (Tovaxin) over a similar treatment (in my understanding of the theorys) already in Phase 3 [(T-Cell Vaccination (aka TCV-01-002) (Sheba Medical Center)] ??
Several people at Sheba are on Opexa's scientific advisory board. Cohen, who is considered to be the father of the T-cell vaccine (he started researching it in the early 1980s), is a contributor to Opexa. They are not competing.

If you look at the history of the T-cell vaccine that Lyon has posted on his site, http://www.msu.edu/~lyonro/tovaxinhst.html you will see that Zhang at Baylor in the late 1990s was at a 40% reduction in attacks, Sheba in the early 2000s had a 60% reduction, and Opexa currently is in the 90% range. The material also shows the progression in the proteins and peptides used to create the vaccine.

Posted: Mon May 21, 2007 2:40 pm
by IHaveMS-com
I forgot to mention. I think the FDA does not approve drugs based on trials run in another country. Maybe someone can elaborate on that.

I know with the RA vaccine that Opexa is working on, the FDA accepted the phase I/II study done in China as preclinical evidence that Opexa could start a phase I/II trial in the US.

Posted: Mon May 21, 2007 2:54 pm
by dignan
Tim, I'll take a crack at your out-of-country research question. I looked into this a few months back and I THINK, if you conduct the research properly, the FDA will approve a drug regardless of the location of the trial, based on the quoted info below:


Research conducted at foreign sites
In contrast to U.S. research, FDA does not require sponsors of foreign-based research to conduct research under an IND, although these sponsors can choose to do so.

Foreign research conducted under an Investigational New Drug Application.
Sponsors of foreign-based research who choose to submit an IND to FDA must also conduct research according to FDA regulations. However, FDA has less information about this research than it does for U.S. based research because it does not track investigators through a comprehensive database of signed attestations.

Foreign research not conducted under an Investigational New Drug Application.
If sponsors submit an NDA containing foreign research that was not conducted under an IND, that research must adhere to FDA regulations for foreign clinical studies not conducted under an IND. This type of foreign clinical research must be conducted according to the ethical principles of the Declaration of Helsinki, or the countries’ own regulations, whichever offers the greater protection to the human subject. Many countries have adopted the Good Clinical Practice guidelines from the International Conference on Harmonization as their regulatory standard. Sponsors are not required to obtain attestations for investigators conducting research under these guidelines.

http://oig.hhs.gov/oei/reports/oei-01-00-00190.pdf

Posted: Mon May 21, 2007 4:36 pm
by IHaveMS-com
Hi Digman,

Interesting reading, but the 58-page report seemed more like recommendations and statistics than actual FDA rules. It seems that I periodically hear about a drug that is approved in some other country, but we cannot get it here. I don't think a pharmaceutical company would pass up the US market if the foreign data was easily excepted by the FDA.

I have another question that you might have come across the answer to. When Opexa set up the IIb trial, it was structured so that it would easily transition into a phase III without a lot of protocol red tape. I would like a good explanation of the difference between a II, IIa and a IIb study and will any one of them get you to phase III quicker.

Posted: Mon May 21, 2007 5:28 pm
by dignan
Tim, you're right about that document not being specifically all about the FDA's rules and regulations. The FDA.gov website gives me nightmares. Imagine, if you will, a maze. Not one of those fun corn mazes in a farmer's field that you'd pay to do -- no no, imagine a mind-bogglingly boring maze. That is the FDA.gov website.

Anyhow, the report I linked to is from the US government's Department of Health and Human Services, so I really doubt that they made a factual error about something like clinical trial procedure, but it is possible.

On the phase IIa vs IIb, see my first paragraph above. But I did find an interesting article that basically says there are no hard and fast rules about IIa vs IIb trials. Here it is:

http://pharmalicensing.com/articles/dis ... d42aebbc76

If somebody else can find more authoritative sources for this stuff, that would be great because it's making my head spin...although that could just be my MS acting up...

Posted: Mon May 21, 2007 6:13 pm
by IHaveMS-com
Hi Digman,

Excellent article. I see why I could not find anything using a search of site:gov. The author even quoted Shakespeare. I will post in a small part if others might be interested.
The FDA's Jenkins insists there is no official definition of Phase IIa, Phase IIb or even plain old Phase I, Phase II, and Phase III trials. He did explain that, generally speaking, early Phase II -- or Phase IIa -- studies look at the absorption, metabolism and pharmacodynamics of a drug rather than at clinical benefit or safety. The second stage of Phase II development -- so-called Phase IIb studies -- "will look more like Phase III trials" because they are looking for clear indications of clinical efficacy and safety in larger groups of patients.

Posted: Tue May 22, 2007 3:41 am
by CureOrBust
IHaveMS-com wrote:Several people at Sheba are on Opexa's scientific advisory board. Cohen, who is considered to be the father of the T-cell vaccine (he started researching it in the early 1980s), is a contributor to Opexa. They are not competing.
Even more reason to think that the treatment will be available (in at least one country) before (and as effective) as Tovaxin.

So why are people not so excited about it? Or is it just that america has a greater penetration on english web sites?

Posted: Tue May 22, 2007 9:08 am
by IHaveMS-com
Hi Cure,

Tovaxin is a trivalent formulation of attenuated myelin-peptide reactive T cells (MRTCs), which are derived from peripheral blood and produced ex vivo as myelin basic protein (MBP), proteolipid protein (PLP) and
myelin oligodendrocyte glycoprotein (MOG) reactive T cells. Opexa uses approximately 100 different peptide fragments from these 3 major myelin proteins to identify an individual's MRTC set.

My guess is that Cohen is using only two of the protein molecules and a small number of peptide fragments. I have read a few of his papers, but I don't know exactly what he is using. If you are interested, you can contact Irun R. Cohen Irun.cohen@weizmann.ac.il and see if he will send you a link to something that describes his process and if he would explain the differences between his work and what Opexa is doing.

Posted: Wed May 23, 2007 1:12 pm
by Lyon
CureOrBust wrote:Even more reason to think that the treatment will be available (in at least one country) before (and as effective) as Tovaxin.

So why are people not so excited about it? Or is it just that america has a greater penetration on english web sites?
Hi Cure,
Not to embarrass Tim or rile people who were down on Tim and his brothers a year ago, but I think there are a couple of good reasons that Tovaxin is more accepted.

First, as Tim hinted, Tovaxin seems to be a more effective and polished product and second, it seems obvious that we wouldn't know nearly as much about Tovaxin if it weren't for Tim and his brothers and their webpage.

Realistically if it weren't for Tim and his brothers, in our eyes, Tovaxin would be much like the Sheba product is currently. Something we'd heard of and which sounded interesting, but also something in which meaningful information is unobtainable.

In hindsight it's impossible to be 100% confident of what my wife and I might have done otherwise, but otherwise we wouldn't be considered clinical trial kind of people. She was recently diagnosed and her MS seemed to be mild. Despite the fact that being diagnosed with MS is a desperate situation in itself, we weren't at the height of desperation and I highly doubt we would have considered ANY clinical trial if I hadn't gotten interested in the "Tim Wesner" controversy (after the fact) which caused me to search and read everything I could about Tovaxin in order to follow the controversy.

I guess it might be said that those who were deriding Tim did far more to promote long term, widespread interest in Tovaxin than Tim and his brothers alone ever could have :oops:

Bob

The "Tim Wesner contreversy"?

Posted: Wed May 23, 2007 1:54 pm
by havingms
Dearest Lyon,
Can you explain to me what the "Tim Wesner Contreversy" is?
Thanks

Posted: Wed May 23, 2007 5:45 pm
by IHaveMS-com
Hi Havingms,

I will explain. When I first stared posting on this site I did not include the disclosure that is now part of my signature. I should have, but didn't. Hindsight is 20/20. I did not post for 7 or 8 months after that, but I was getting quite a few private email asking questions about being in the trial, so now, I post in spurts. When I look in and see some questions that I can answer, I do a few post, and always include my disclosure. You can read more about my family's participation on my site.

Posted: Wed May 23, 2007 5:55 pm
by Lyon
Whew! Thanks Tim!

Honestly, I've been sitting in front of the computer for 45 minutes trying to come up with the proper response.

I'm sorry I brought the issue up but I'm still convinced I gave Cure the most accurate answer.

My wife and I got back from her second treatment earlier today. At her first treatment 4 weeks ago she was not only the first person in the Michigan leg of the Tovaxin IIb trial, but also the only person. Since then the situation for five other people have resolved so Michigan now has a total of 6 people in the IIb, which I think is a pretty good turnout.

Thanks again Tim....and sorry about reopening old wounds.

Bob

Posted: Wed May 23, 2007 5:59 pm
by IHaveMS-com
Hi Bob,

It was a self-inflicted wound. I think I have healed. I hope everyone else has.

Posted: Wed May 23, 2007 6:12 pm
by Lyon
IHaveMS-com wrote: It was a self-inflicted wound. I think I have healed. I hope everyone else has.
:lol: Of course I'm biased because I'm convinced that my wife and I are better off due to your oversight. With that in mind I couldn't be happier that things worked out as they did.
Bob