Giving a special peptide drug daily to mice with clogged arteries helped reduce the size of the blockages by about one-third, compared to mice that didn’t get the drug.

Mice treated with the drug had much smaller dead-cell areas in their artery plaques—almost half as big—which might mean their plaques are less likely to break open.

The drug didn’t lower the mice’s overall cholesterol, so its benefits must come from something else—like reducing inflammation or cell death in plaques.

The mice didn’t gain or lose weight or eat differently with the drug, so the benefits aren’t just because they were eating less or changing their metabolism.

The drug lowered the levels of two proteins in the arteries that are known to break down plaque structure, which might help keep plaques from bursting.

The drug didn’t affect blood sugar or fat levels in the blood, so its benefits aren’t due to improving how the body handles sugar or fat.