Piper Jaffray analyst Edward Tenthoff lowered his price target for Sarepta Therapeutics to $168 from $189 and keeps an Overweight rating on the name following the company's Q3 results. Exondys51 sales were in-line at $78.5M in Q3 and management reiterated guidance of $295-$305M for this year, Tenthoff tells investors in a research note. He believes Exondys51 sales of $300M this year "are plateauing" and now forecasts $344M of sales in 2019. The analyst, however, says micro-dystrophin GeneRx is advancing and could treat up to 70% of Duchenne muscular dystrophy boys. He thinks this will erode exon-skipping sales upon approval in 2020.