Washington ? In an unusual step, a dozen competing drug companies have agreed to share data on thousands of Alzheimer’s patients in hopes that the extra information will spark new ideas for treatments.

The database being announced today covers 4,000 patients and counting. It was created in consultation with government regulators and the National Institutes of Health.

The effort may sound wonky, but attempt after attempt to create new Alzheimer’s medications — ones that might help before too much of a person’s memory is destroyed — have failed.

In pooling resources from clinical trials, scientists can hunt trends that may suggest what to study next. The database also will be available to brain researchers not affiliated with drug companies, to compare their own findings, and eventually will address other neurodegenerative diseases such as Parkinson’s.