FDA documents show how controversial Alzheimer's drug decision was reached

New documents released Tuesday depict, in greater detail, how staff at the Food and Drug Administration were not in agreement as the agency weighed whether to approve a controversial new treatment for Alzheimer's disease.

For months, it was known that the FDA team responsible for evaluating the statistical analyses used in clinical testing did not believe there was enough evidence to approve the drug, which is now called Aduhelm and was developed by the pharmaceutical companies Biogen and Eisai.