Eisai Co.’s Alzheimer’s disease drug developed with Biogen Inc. gained support from advisers to US regulators, paving the way for a likely full regulatory approval that could lead to broader insurance coverage.

The six advisers to the Food and Drug Administration voted unanimously to recommend the traditional approval of Leqembi, which is the first treatment clearly shown to slow the progression of the disease that impacts more than 6 million Americans and some 55 million people around the world. The favorable vote was widely expected by analysts after the FDA’s staff supported the drug in a report Wednesday.

Eisai shares climbed as much as 6.2% in early trading in Tokyo on Monday, bringing their rise this year to about 24%. Biogen shares were halted Friday.

The drug sailed through the hearing with the vote after just a short, 20-minute discussion during which every panel member agreed that the drug has been shown to be effective in slowing cognitive and functional decline.

“The evidence for clinical benefit was very clear and very robust,” said panel member Merit Cudkowicz, a neurologist at Harvard Medical School. “These are meaningful changes for people with Alzheimer’s.”

But panel members were worried about the potential risks of the drug in certain categories of patients, including patients on certain types of anticoagulants. The drug can cause brain swelling and bleeding, and anticoagulant use may exacerbate such bleeding. Some panel members thought people on anticoagulants should be warned against using these drugs, though others said there wasn’t enough data to make a clear decision.

Anticoagulant Risks

Cudkowicz said she was leaning toward recommending excluding people on anticoagulants from using the therapy, saying this is where additional data and studies would be helpful.

“This is where I don’t think the benefit outweighs the risk,” Cudkowicz said.

Leqembi was earlier cleared under the agency’s accelerated approval pathway in January based on its ability to remove deposits of a toxic protein called amyloid from Alzheimer’s patients’ brains. But Medicare, the US health program for older adults, declined broad coverage for Leqembi and similar agents without full FDA approval of data showing an impact on cognitive decline.

That makes the FDA’s pending decision crucial for Leqembi’s US sales prospects of more than $2 billion annually, according to Bloomberg Intelligence analysts Marc Engelsgjerd and Sam Fazeli. The agency is not required to follow the advice of its advisers, but usually does.

The agency’s final decision is expected by early July. The Centers for Medicare and Medicaid Services said recently that broader coverage would start immediately upon full approval.