Well thats a great post, and it highlights the conundrum
"But time, says Barker, will best establish efficacy. In most trials the end point is no more than a year after the treatment. That may not be long enough: implanted cells or injected growth factors might take longer than this to become fully functional, and the placebo effect may not have had time to dissipate. "We want a 3–5-year endpoint," says Barker.
There are hints from some of the failed phase II trials that patients followed up beyond study endpoints might tell a more positive story
4. Some say, therefore, that sham controls are sinking the prospects of valuable drugs. Anders Björklund, a neuroscientist at Lund University in Sweden who is collaborating with Barker, says that sham surgery can lead researchers to throw out a strategy prematurely if the trial fails because of technical or methodological glitches rather than a true lack of efficacy."
If you accept that sham surgery works in PD by stimulating dopamine release AND can continue to affect performance for 2 years then sham surgery is not "no treatment". So in that regard it could be masking the benefit from NTcell.
So really we can't know the outcome until after the placebo effect has dissapated. If a subgroup of patients still has a durable response in two years time while the placebo patients have deteriorated, then we will know if NTcell worked on some but possibly not all of the trial patients. But that would be 18 months away.
Right now though the market knows plans for commercialisation have been shelved and possibly concluded that NTcell "doesn't work".I think the second part is premature, since 3 of the first 4 patients do seem to have had a sustained durable response now over several years.
I belong to the group that believes that embryological dopaminergic implants have been shown to work provided that the treatment is given before global damage is too severe, and that side effects can be limited by not implanting an excessive number of dopaminergic cells and the cells are implanted by distributing them uniformly along the length of the putamen. But thats' quite a lot of provisos. Blinding of course is only possible with sham surgery, but not with DBS.
