Despite a 99 percent failure rate and another major setback last month, Alzheimer’s researchers are plowing ahead with hundreds of experiments — and a boost in federal money — to try to a crack a deadly disease that has flummoxed them for decades.

A law passed by Congress in December and signed by President Obama sets aside $3 billion over 10 years to fund research of brain diseases and precision medicine, a shot in the arm for Alzheimer’s research. The law, called the 21st Century Cures Act, also includes prize money to encourage Alzheimer’s experiments.