Sarepta (SRPT) is rising after JMP Securities analyst Liisa Bayko wrote that a competing drug will not likely be approved until 2014 or 2015. Dispersen, a Duchenne muscular dystrophy treatment developed by GlaxoSmithKline (GSK) and Prosensa, is not expected to be approved until 2014-2015, GlaxoSmithKline announced this weekend, according to Bayko. The delay will remove an overhang from Sarepta, the analyst believes. Moreover, Prosensa has had some difficulties with its drug, added, Bayko. Shares of Sarepta can rise significantly over the long-term and short-term, and investors should own the shares into 2013, she wrote. In mid-morning trading, Sarepta jumped $2.19, or 9.58%, to $24.94.