Biotechnology US RNA-based drug developer Sarepta Therapeutics (Nasdaq: SRPT) saw its shares leap 140% to $8.30 yesterday after the company, formerly known as AVI BioPharma, announced that treatment with its exon-skipping compound, eteplirsen, achieved a significant clinical benefit on the primary clinical outcome, the 6-minute walk test (6MWT), over a placebo/delayed treatment cohort in a Phase IIb trial in patients with Duchenne muscular dystrophy (DMD), a devastating progressive, degenerative, universally fatal neuromuscular disorder that affects about one in every 3,500 boys worldwide. 25 July 2012