An Experimental Alzheimer's Drug Fails in a Clinical Trial

A potentially promising drug for the prevention of Alzheimer's disease has failed in a key clinical trial, according to Eli Lilly, the drug's developer. In a study involving more than 2,000 patients with early signs of dementia, the drug, known as solanezumab, failed to prevent the advancement of the cognitive impairment that accompanies dementia and that leads ultimately to Alzheimer's disease.

The results were disappointing, but not all that surprising. So far, no drug has been able to prevent the progression of dementia once it has started. Researchers are reluctantly coming to the conclusion that by the time dementia first becomes apparent, it is already too late to affect the future course of Alzheimer's disease.

Whether solanezumab could prevent the development of dementia if it were given before the first signs of dementia is not known. Sadly, it may never be known. That's because it would be prohibitively expensive to conduct a drug study involving tens of thousands of seemingly normal people, in the hope of observing an effect on the few people among them that will ultimately develop dementia.

So we're at an impasse at the moment. There are several drugs on the market that can reduce (at least temporarily) the symptoms of the dementia associated with Alzheimer's disease, but there are no drugs that can prevent the slow progression of the disease. There aren't even any on the horizon, apparently. Don't expect progress any time soon.