Just a few points on the trial: This was purely EU based, in fact all the trial centers were based in France, hence there should not be a listing on clinicaltrials.gov. I know its very annoying not to be able to verify trials there, but unfortunately Europe does not yet have the same level of openness in regulatory and government matters as at least some areas do in the US.....
The difference to tetrabenazine is that RP-103 is a disease modifying treatment. Tetrabenazine reduces the chorea sysmptoms associated with neural degeneration in HD, but it does not alter the underlying neural degeneration or the long term (uniformly fatal) course of this disease.
RP-103 is disease modifying, i.e. it changes the course and progression of the underlying neural degeneration, the change in symptom score is measured to follow how much improvement to the disease course can be achieved.
It is a little bit like the difference of taking a painkiller to reduce symptoms in say cancer and getting chemo with a view to slowing down or curing the underlying disease
Very funny, the 2007 estriol trial results have not been reported because that is the study that is due to be reported this year..... It's just that since 2007 the NIH and the US Nat. MS society have added lots more funding and just about every major university in the US that is involved with MS has joined the study!
Sometimes clinicaltrials.gov is truely helpful.