How much research?

I was curious as to how much research has been done on Alzheimer's disease itself, and how much in search for a cure.

Today’s research more often target the causes of Alzheimer’s in order to develop disease modifying drugs that will ultimately prevent the disease itself.
NIA- National Institute on Aging (Alzheimer's Disease Education and Referral Center)
The NIA, one of the 27 Institutes and Centers of NIH, leads a broad scientific effort to understand the nature of aging and to extend the healthy, active years of life. The NIA supports and conducts genetic, biological, clinical, behavioral, social, and economic research related to the aging process, diseases and conditions associated with aging, and other special problems and needs of older Americans. The NIA is the primary Federal agency for research on Alzheimer’s disease.

Scientists are making huge advances in identifying potential interventions to diagnose, slow, prevent, treat, and someday cure Alzheimer’s disease. As of today there are more than 90 drugs in clinical trials, and many more waiting for FDA approval to enter into the stage of human testing.