LONDON (Reuters) - European regulators are following in the footsteps of the U.S. Food and Drug Administration with plans to help pharmaceutical companies win approval for novel Alzheimer’s drugs that treat the earliest stages of the memory-robbing disease.

The European Medicines Agency said on Wednesday its new guidance would encourage the testing of new medicines even before symptoms appeared, as well as the potential use of biomarkers, such as signs of protein build-up in the brain.

Experimental Alzheimer’s drugs have had a dismal track record, with more than 100 failures, including most recently a treatment from Merck, while Pfizer said in January it was quitting the field.

But researchers are not giving up. Hopes are now pinned on being able to intervene earlier and on diagnosing at-risk patients by screening, imaging or biomarkers.

The latest science suggests biological changes associated with Alzheimer’s start to occur as early as 10 to 20 years before clinical symptoms appear, putting a premium on catching patients before their disease progresses.

The European drugs agency said its guidance was expected to facilitate development of medicines to both prevent and treat the condition. Currently available Alzheimer’s drugs can only treat its symptoms.

Scientists and drug company executives have welcomed the rethink on both sides of the Atlantic, which was kicked off by FDA proposals on Feb. 15.

Andrea Pfeifer, chief executive of Switzerland’s AC Immune, which has one of the industry’s broadest Alzheimer’s pipelines, said the new guidelines would cause her company to look again at the design of a mid-stage vaccine trial starting soon.

She particularly likes an FDA suggestion that early-stage therapies could be developed by showing benefit on just cognition, rather than having to show an impact on function, or the ability patients to do things like wash and dress themselves.

“For the Phase II trial of our vaccine, we might give cognition a higher priority because it is easier to measure and it is more sensitive,” Pfeifer told Reuters during a visit to London.

However, she said the new regulatory guidelines were unlikely to change existing clinical trials.

Testing patients for cognitive changes like an improvement in memory and thinking ability is easier and less intrusive than tracking their functional performance.

There is no cure for Alzheimer’s, the most common cause of dementia in the elderly, which destroys brain cells and disrupts essential messaging systems in the brain. According to the World Health Organization, 35.6 million people have dementia worldwide and this number is expected to double by 2030.