THURSDAY, April 17 (HealthDay News) -- A new analysis of a study on an experimental Alzheimer's drug reinforces the notion that the compound is broadly effective at improving the cognitive function of mild to moderate Alzheimer's patients.

A second analysis of the trial on the medication, known as Dimebon, also reveals that by improving the Alzheimer's patients' ability to perform daily tasks, the drug shaves off almost an hour a day in the amount of time the average caregiver must attend to his or her patient.

The twin observations raise hope for a new and improved therapy to address both the symptoms and the underlying mechanisms driving a disease that the Alzheimer's Association says currently affects more than 5 million Americans.

"The broad context is that there are treatments available that treat Alzheimer's symptoms, but do not slow the disease down or prevent it," explained Steven H. Ferris, director of the Alzheimer's Disease Center at New York University. "So, we really need drugs that are more potent and safe and that actually slow the disease down."

"And this drug has that potential," he said. "It still needs more research -- which is going to happen. But, so far, it really looks like it might have a better effect than existing drugs and also a better side effect profile."

Ferris is expected to discuss the new research on Dimebon on Thursday at the American Academy of Neurology annual meeting, in Chicago.

He pointed out, however, that he played no role of any kind in the initial analysis of a recently completed yearlong study that had looked into the drug's prospects.

Ferris describes his current connection to the Dimebon study as that of a paid "external scientific advisory board" member to drug maker Medivation Inc., engaged in helping the company interpret the findings to date while moving forward with future study plans for its drug. He has no equity in the company.

The original study -- funded by the San Francisco-based Medivation Inc. -- had been conducted in Russia, under American guidance and supervision.

The authors of that effort first released preliminary findings last June on the safety and effectiveness of the experimental drug among 183 mild to moderate Alzheimer's patients.

At the time, the researchers concluded that Dimebon helped boost patient memory and clinical function, while also improving the ability to think and engage in daily activities -- without prompting major side effects.

They noted that the new drug packed the symptom-fighting punch, in effect, of both an anticholinesterase drug (such as Aricept) and another class of medications known as glutamate antagonists. As well, the authors claimed that Dimebon also protected brain cells from Alzheimer-causing amyloid build-up, thereby defending against disease progression itself.

Ferris said that Thursday's presentation is essentially a "secondary look" at these initial conclusions.

The first finding is based on a number-crunching of cognition tests run at the 12-, 26-, 39- and 52-week study marks. The analysis revealed sweeping improvements in terms of memory (such as word recall, recognition, and instruction recollection); orientation; the ability to perform complex activities; and language comprehension.

The second finding -- based on the same tests -- observed that patients taking Dimebon were better able to take care of themselves in basic ways, such as being able to eat and prepare a meal, use the toilet, use the phone, read, use appliances, keep appointments, and hold a conversation.

As a result, the study authors said that caregivers saved 51 minutes a day on average in the time they spent caring for an Alzheimer's patient.

"What's new here is that we're looking in a more specific way at the nature of the drug's cognitive effect," he said. "To see whether it's narrow or broad. And what we found is that it's a broad effect. Virtually all of the health categories we looked at showed a significant treatment benefit, and the time spent by the family member having to deal with the patient was actually reduced."

Greg M. Cole, associate director of the Alzheimer's Disease Research Center at the UCLA David Geffen School of Medicine, said the new analyses appeared to be consistent with initial study findings. But he added that much more research is needed.

"We see that this drug improves patient outcome relative to taking nothing," he noted. "But the real question is how does Dimebon compare with the standard of care today? That's what remains to be seen."

More information

For additional information on current symptom treatment options for Alzheimer's, visit the Alzheimer's Association.