CytRx ( CYTR) rose 20% Tuesday after saying its lead drug candidate, arimoclomol, was granted orphan medicinal product status for the treatment of amyotrophic lateral sclerosis by the European Commission.

The Los Angeles-based biotech said the status move grants CytRx market exclusivity in the European Union for 10 years in the event that arimoclomol receives marketing approval, and provides for incentives such as reduced fees for protocol assistance and scientific advice.

"We appreciate the European Commission's recognition of arimoclomol as a potential drug for ALS," said CEO Steven A. Kriegsman. "This is a life-threatening and debilitating condition for which there is currently no effective treatment, and we believe that arimoclomol is based on a novel mechanism of action that may hold a key in ALS therapy."

Shares rose 26 cents to $1.57.