While better new drugs are urgently needed to treat neurodegenerative diseases, developing them is too complex and expensive for big pharmaceutical companies. Research and development that costs millions of dollars can fail at any time and the investment is risky. 
The average drug development cycle is only 1.2 years, while neurodegenerative drugs take 6 to 10 years.
 big pharmaceutical companies cannot be expected to invest in drugs to treat neurodegenerative diseases.