Medicines Co said its experimental anti-clotting drug met the main goal of a late-stage study, sending its shares up as much as 13 percent in early trade to a near six-year high.
The company said the drug, generically called cangrelor, showed statistically significant results, compared to another clotting disorder drug, clopidogrel.
Cangrelor is prescribed to patients who have to undergo a stent-placing surgery or a bypass and prevents formation of clots during such procedures.
"It is a very niche specialty market ... Our peak sales for (cangrelor) are $300 million," ISI Group analyst Umer Raffat said.
Bleeding rates are important for anticoagulants such as cangrelor since a high rate could trigger an adverse event.
However, Raffat said the bleeding rates during the late-stage study were similar to prior trials.
Clopidogrel is marketed by Bristol-Myers Squibb Co and French drugmaker Sanofi under the brand name Plavix, which lost its marketing exclusivity in the United States last May.
Medicines Co said on Tuesday it expects to submit data from the late-stage study on cangrelor for regulatory review in the United States and European Union in 2013.
Shares of the New Jersey-based company touched a high of $29.29, before giving up some gains to trade up 12 percent at $29.01 on the Nasdaq.
(Reporting By Pallavi Ail in Bangalore; Editing by Sriraj Kalluvila)