Just when Sarepta Therapeutics had some news to get excited about, the company now has to brace itself for what could be a pretty big setback. The Bothell, WA-based biotech company (NASDAQ: SRPT) said last month that its experimental RNA-based drug for Duchenne Muscular Dystrophy showed some encouraging signs of improving walking ability for boys in a small clinical trial, which caused its shares to more than double. But the company’s R&D efforts were dealt a blow late last week when the U.S. Department of Defense ordered it to stop working on a lucrative defense contract as the government assesses budgets, and whether to terminate the program.