Piper Jaffray analyst Danielle Brill reiterates an Overweight rating on Sarepta Therapeutics provided a nine-month update for all four patients in its Phase 1 microdystrophin gene therapy trial. Results showed "marked improvements" in the NorthStar Ambulatory Assessment for all patients while creatine kinase level spikes were also observed, Brill tells investors in a research note. The analyst attributes the CK spikes to spikes to physical exertion and finds them "not worrisome." CK levels trended down for patients and the functional data continue to look encouraging, Brill contends. She stays bullish on Sarepta shares. The stock in afternoon trading is down 2%, or $2.99, to $119.27.