Sarepta Therapeutics Inc.’s miss on a key phase II ambulatory endpoint in its Duchenne muscular dystrophy (DMD) trial may have been caused by a dramatic disparity in functional ability at baseline among older vs. younger patients afflicted with the progressively worsening disorder. In any case, Wall Street had knives out, carving 51% of the value away from shares (NASDAQ:SRPT) of the Cambridge, Mass.-based firm, which closed at $82.29, a loss of $86.66, or 51%.

Bone Health Technologies Inc. may be on the verge of upstaging a common drug therapy, but don't tell them to break a leg. The San Francisco-based company's Osteoboost Vibration Belt received a U.S. FDA breakthrough designation for technology that delivers gentle stimulation to reduce bone loss and prevent osteoporosis with the goal of reducing the number of potentially devastating broken bones in the elderly.