I don't want to come out and name companies or anything and I am not really sure how much has been released to the public so far.
My understanding is that the primary cause of the problems is the formation of inclusion bodies inside neural cells that interfere with cell functioning. There are some molecules that can dissolve these bodies without harming the cells but it has been almost impossible to get those molecules into peoples brains and then into the cells where it could work and so the stuff only worked in a petri dish pretty much. However, one company recently figured out how to make a chaperone molecule that can be attached to the target molecule that will cause most of the target molecule to be taken across the blood brain barrier and inside the cells where it can be effective.
I don't know anything about avoiding zinc or aluminum only about the formation of inclusion bodies due to misfolded proteins that also cause other proteins to misfold. At least with some of the research I have read and some of the researchers I have talked to it looked like cell function was restored once the inclusion bodies where removed.
Genetic manipulation is absolutely the long term way to fix this and there is a lot of work being done on that also. Thankfully genetic manipulation works on adult organisms and not just in the few cell stage of development.