Eisai’s Alzheimer’s drug Leqembi gained full approval from U.S. regulators, a move that will help widen insurance access to the first drug cleared based on its ability to slow progression of the mind-robbing disease.

The broader clearance from the Food and Drug Administration marks a milestone for treatment of the dementia that afflicts some 6 million Americans. It’s expected to lead to far greater coverage by insurers and the federal Medicare program for the medicine from Eisai and its partner Biogen, which received expedited approval in January. The drug costs $26,500 for annual treatment.

Patients taking it need MRI scans to monitor for early signs of side effects that can include swelling and bleeding in the brain. The label includes a prominent black-box warning about the potential for these conditions, which are usually asymptomatic but in rare cases can lead to life-threatening complications. The warning also notes patients with a certain gene mutation called APOE4 have a higher risk of such side effects.