Roche said on Friday its gantenerumab antibody had received breakthrough therapy designation from the U.S. Food and Drug Administration for the treatment of Alzheimer's disease.

Like many other drug prospects to treat this debilitating disease, gantenerumab is designed to neutralize beta-amyloid plaques seen as a driver behind brain cell death.

The Swiss pharmaceutical giant said the U.S. breakthrough designation was based on data showing that gantenerumab had significantly reduced brain amyloid plaque in ongoing trials.

Levi Garraway, chief medical officer and head of global product development at Roche, said the designation "reinforces our confidence in gantenerumab, which would be the first subcutaneous medicine for the treatment of Alzheimer's disease with the potential for at-home administration."

Analysts had said there could be an expedited filing for U.S. regulatory approval of gantenerumab, which could be a blockbuster if shown to work.

Pursuit of an Alzheimer's remedy, which would inevitably reap drugmakers billions of dollars, has been marked by more than 100 failures, although researchers still hope to tame a condition that affects nearly 6 million Americans, more than 40 million people worldwide, and which is growing more prevalent.

Roche will complete a Phase III trial of the medicine in the second half of next year. In July, Chief Executive Severin Schwan said it was urgent to find a way to treat this unmet medical need and bring treatment to patients as soon as possible.