Phase II clinical data for drisapersen from GlaxoSmithKline plc (LSE:GSK; NYSE:GSK) provided grist for supporters and skeptics of a competing Duchenne muscular dystrophy (DMD) candidate from Sarepta Therapeutics Inc. (NASDAQ:SRPT).

Sarepta's shares are up over 1,000% since summer, based on data from an extension of a Phase IIb trial of eteplirsen in 12 DMD patients. Reports in the lay press have contributed to the run-up.