The U.S. Food and Drug Administration on Monday approved Medicines Co's blood clot preventer Cangrelor, which has faced multiple setbacks since it first entered late-stage studies close to a decade back.

Cangrelor, also known as Kengreal, is an intravenous therapy aimed at preventing blood clots in patients who need percutaneous coronary intervention (PCI) or angioplasty, a non-surgical procedure to widen narrowed or obstructed arteries.

Heart diseases are the leading cause of death in the United States, accounting for one in every seven deaths, according to the American Heart Association.

Medicines Co has funneled about $200 million into developing Cangrelor over the past decade, which included two unsuccessful trials and a pivotal study last year that drew scathing criticism as well as a rejection from the FDA.

In its complete response letter at the time, the agency asked the drugmaker to go back to the drawing board and reanalyze data from the Champion-Phoenix trial, which included about 11,000 patients.

The company, which licensed Cangrelor in 2003 from AstraZeneca Plc, tweaked the study and narrowed the indication of the drug and its target population.

The move convinced a majority of an independent advisory panel to the FDA two months ago that the drug could be used as a second-line therapy and had a better safety profile than Bristol-Myers Squibb Co's Plavix, known generically as clopidogrel.

In a trial that compared Cangrelor to Plavix, Cangrelor significantly reduced the occurrence of heart attack, the need for further procedures to open the artery and stent thrombosis, the FDA said in a statement on Monday. (1.usa.gov/1H7H88S)

Medicines Co said in a statement that it expects Cangrelor to hit the market as early as July.

But the series of setbacks is likely to have taken its toll on the potential market of the drug.

RBC Capital Market's Adnan Butt expects Cangrelor to rake in peak annual sales of about $80-$100 million in the United States.

That pales in comparison to the more than $200 million the company is estimated to have spent to develop the drug over the past decade, according to regulatory filings.

Still, Cangrelor's approval is the third for Medicines Co in the past three months and comes as Angiomax, its lead product and biggest revenue contributor, faces a potential threat from generics.

The company's shares were up 1 percent at $29.64 in late afternoon trading on the Nasdaq.