Ok...........I'll do my best to answer these, but some of them unfortunately don't have "good" answers, but your questions are excellent ones! (Be careful, you might end up finding yourself in my boat as a result of asking good questions - especially directly from the medical professionals.
(i) Does the Tysabri data only relate to the relapses that are noticed by the sufferer?
That's the problem. Nobody knows. The data is way too "skewed" to make real heads or tails of it. And it depends on what you believe (if you are a doctor) about what is really happening progressively speaking, in MS. None of which has been proven. So, depending on which doctor you are speaking with and his "particular" beliefs regarding MS and how it acts, you'll get many numerous answers to this, none of which can be proven.
(ii) Why is there never any progress in getting them on the list of approved ms drugs - their safety has been proved already?
First, it's extremely difficult to buck the "system", and second, it all revolves around how much "money" can be made from the drug(s).
How much influence do the major drugs companies have over our national drug approval bodies or our governments?
bromley, you'd be shocked if you knew the whole story (speaking solely of the U.S.) Let's just leave it at right now, with the Republicans having control of the country, let's just say they have "lots" of influence. (And that's putting it nicely.)
(iii) If any prove very effective in just the first year of the Phase III trial - what would prevent me as a private citizen from signing a piece of paper to say I want to take them and I'm prepared to take the risks i.e. would not sue the company if I got ill / died?
Nothing could prevent you from indemnifying them from legal liability, but that would do nothing for their "profit margin" or "market share" or "stock prices", should someone get ill or die during one of their trials. So, there is more than one consideration that they look at here. Risk assessment in the situation as you suggest would prove itself to not be worth it in most cases.
Can the system be bypassed?
Not very easily. Hence why we have "unions" and legislative advocacy (and lawsuits). Their stronghold is extremely impenetrable.
(iv) How would the new myelin be of benefit if it sits over scar tissue?
Good question, bromley. Especially since it is not demyelination that causes disability in the first place. It is axonal damage (that often happens WITHOUT demyelination taking place at all). I believe the thought by "some" (who in my opinion are still a bit behind the current proven position regarding the pathogenesis of MS), is that if you remyelinate in time BEFORE the glial scar is formed, then you could prevent the axon from becoming damaged. But, as I said, that is still "assuming", which has since been proven to be a false assumption in many patterns of MS, that demyelination happens "first" before axonal degeneration. In progressive MS, that is not the case. So, in my opinion.......I'd say it's probably going to be a waste of money in the long run for MS, but will help some demyelinating diseases. There are other demyelinating diseases that are NOT Multiple Sclerosis.