* European, US health regulators grant orphan drug status
* Shares up 5 pct
March 8 (Reuters) - ImmunoGen Inc (IMGN.O) said its experimental skin cancer drug received orphan drug designation from U.S. and European health regulators, sending its shares up 5 percent in after-market trade.
ImmunoGen is developing IMGN901, which is currently in an early stage trial, for the treatment of Merkel Cell Carcinoma -- a form of skin cancer that typically occurs on the head or neck.
Orphan drug designation is granted by the U.S. Food and Drug Administration (FDA) to drugs or biologics that treat a condition affecting less than 200,000 Americans.
The status grants the drugmaker a marketing exclusivity of seven years in the United States, upon approval.
Similarly, in the European Union, orphan drug designation is granted to drugs or biologics that treat life-threatening or chronically debilitating conditions affecting no more than five in 10,000 people.
Shares of the company were up 38 cents to $7.75 in after-market trade. They closed at $7.37 Monday on Nasdaq. (Reporting by Anand Basu in Bangalore; Editing by Maju Samuel)