Pfizer-J&J Alzheimer drug fails to stop mental decline but may slow brain plaque, studies find

New research suggests that an experimental Alzheimer’s drug might slow formation of the plaque that clogs the brains of people with the disease.

The drug by Pfizer Inc. and Johnson & Johnson failed to stop mental decline, so it won’t help people who have dementia now. But doctors say it might work if given earlier in the course of the disease, before so much damage and memory loss have occurred.

In one study, some people on the drug had lower levels of a substance that forms the brain plaques than others who were given a dummy treatment. They also had less of another substance released when nerve damage occurs.

The results on the drug, called bapineuzumab (bap-ih-NOOZ-uh-mab), were discussed Tuesday at a conference in Sweden.