(REUTERS) - There is new and encouraging data in the fight to combat the memory-robbing disease Alzheimer's.

Eli Lilly presented follow-up data from two large trials of the experimental drug, solanezumab, on Wednesday at the Alzheimer's Association International Conference in Washington.

While previous trials that also included moderate cases were not effective, when Lilly analyzed the results for mild patients, it suggested solanezumab caused a significant 34 per cent slowdown in mental decline, and an 18 per cent slowdown in loss of functional abilities compared to a placebo.

"This is important because we are now getting a longer history with this drug," said Dr William Thies, the Senior Scientist in Residence at the Alzheimer's Association. "It's important that there was no safety signal. There were no additional side effects. It's important because it showed a continued effect of the drug, so the effects aren't transient. '

"They aren't temporary. And it showed that people were willing to tolerate the administration of this medication, which is given by injection."

The drug works by blocking formation of a protein called beta amyloid that is believed to cause toxic brain plaques that are considered a hallmark of Alzheimer's.

Eli Lilly shares have jumped 24 per cent so far this year, compared with average 12 per cent gains for other large drug-makers, largely on faith in the drug.