I don't know why this was downvoted, it's literally true for ALS and most neurodegenerative diseases.
There were 86 phase III unsuccessful clinical trials for ALS. A phase III clinical trial is a huge effort, Each costs tens of millions Dollars.
If you look at phases I, II, and III trials there were 378 of them. There were also 186 trials on managing the disease (without attempting to cure it).
https://clinicaltrials.gov/search?cond=Amyotrophic%20Lateral...
Many people say that ALS research is not enough funded despite all those millions Dollars on trials, I believe this thinking is missing the most important findings from all those unsuccessful trials,
I believe that the paradigm of what is an ALS disease must be completely wrong for clinical trials to be so unsuccessful.
(Caveat: I am not a doctor; just a blogger on research on ALS/Parkinson/Alzheimer's diseases:
https://padiracinnovation.org
)