Biogen Idec presents evidence that its Alzheimer’s drug will be the first to effectively treat the underlying cause of the disease.

The pharmaceutical company had early trials that focused on battling the disease and had confident results. With similar future trials, the new drug will be an automatic money-maker, according to Fortune.

The clinical trial showed a slowing of the cognitive decline and dementia associated with Alzheimer’s, up to an 82% improvement in mental symptoms compared to the control group after a year of treatment.

Biogen said that the developmental drug, known as aducanumab, had significantly reduced amyloid plaque buildup in the brain during the trial, which is considered a contributor of Alzheimer’s disease.

The phase one trial results were so promising that analysts suggested the treatment could eventually be worth at least $10 billion in sales.

The company has a long way to go before winning FDA approval for the drug, but its shares already showed a spike closing 10% higher after they shared the data at a conference in Nice, France.

The pharmaceutical industry has been looking for an effective treatment for Alzheimer’s for a long time. The biggest problem researchers have found is to definitively link a particular gene or marker to the disease. Biogen has been able to confirm such a relationship.

The company’s new drug raises the possibility of treating people with Alzheimer’s by identifying a target for future medications. Drugs that can alleviate dementia and other cognitive symptoms could help more than 5 million Americans who have the disease.

The design of its clinical trial is where Biogen excelled, not with the drug itself. The company carefully screened prospective trial participants using PET scans to make sure they actually had the amyloid plaques that the drug targets.

That additional step is why Biogen’s drug achieved a statistically significant benefit while other companies have failed with their experimental treatments.

If the company can replicate similarly impressive results in subsequent trials, it will have the first blockbuster Alzheimer’s drug on its hands.