As I understand the story, ALS TDI was started by family members of someone with ALS in order to direct research specifically towards an effective treatment for ALS. The founders felt that existing research projects were not getting the job done, perhaps too theoretical, and that a new organization was needed that was oriented towards this one goal. Their main technique has been to work with ALS mice, which have been genetically engineered to have a gene taken from certain human families with ALS, that causes an ALS like disease in the mice. ALS TDI has tested a huge number of drugs and therapies on these ALS mice, trying to find something that extends their lifetime. Unfortunately, by and large they have not had much luck. They got a big increase in funding about 3 years ago, $6 million a year for 3 years from the MDA. I think that is about up but MDA recently put some more money in, I heard.
They did find one drug last year which shows some promise, not a cure but it does extend life in the mice. This is pretty much the only thing they have found to work in almost 10 years of trying. So at this point they are trying to find a pharmaceutical company to partner with and take the drug to the next step so it can be tried in humans.
ALS TDI is legitimate but they do seem to ask for money a lot. Unfortunately that is pretty much the rule with ALS groups, it is not a disease with much funding. Some criticize ALS TDI for focusing so much on mouse research, but at least they do have this one potentially successful drug now, and maybe something will come of that.