Struggle to find dementia treatment yields only frustration

Dementia has unseated AIDS as one of the world’s top killers, new figures from the World Health Organization show, as drugmakers struggle to either curb or cure it.

Alzheimer’s disease and other forms of dementia killed 1.54 million people in 2015, more than twice the number of deaths from the disease in 2000, according to documents posted on the WHO website last month. It replaced HIV/AIDS as No. 7 on the global health watchdog’s list of the 10 biggest causes of death worldwide. New therapies helped push fatalities from HIV/AIDS from 1.5 million down to 1.1 million over the same 15-year period.

Drugmakers have struggled to understand Alzheimer’s, with Merck & Co. abandoning a high-profile study this week, less than three months after a similar defeat for Eli Lilly & Co. More than 100 experimental treatments have failed to slow the condition, which dismantles memories and leaves patients unable to take care of themselves. Dementia afflicts some 47 million people around the world and the number of cases will probably rise to 75 million by 2030, said Shekhar Saxena, director of the WHO’s department of mental health and substance abuse.

“We are making slow progress,” Saxena said, calling for more public money to be directed toward developing treatments. “I am less optimistic than I would like to be.”

Dementia’s climb up the WHO ranking is partly due to the aging of society, and partly to doctors’ diagnosing it more frequently as they grow more familiar with the disease, he said. In high-income economies, Alzheimer’s and other dementia rank as the No. 3 cause of death, trailing only heart disease and stroke. By contrast, HIV/AIDS remains on the top 10 list in the poorest countries, alongside problems such as malaria and diarrhea.

The most recent drug to help treat symptoms of Alzheimer’s is more than a decade old, and there is no cure. Some drugmakers persist: Merck is investing in another study of verubecestat, the drug that failed this week, and Biogen Inc. and Roche Holding are also pursuing potential treatments.