Commenting on weakness in shares of Ionis Pharmaceuticals (IONS), Evercore ISI analyst Josh Schimmer said he knew Spinraza new adds would start to decline at some point, leading to a sequential drop in injections, but this happened "a bit early." Following Biogen's (BIIB) report, he sees potential for Spinraza stagnation in the U.S. this year, with growth driven outside of the U.S. In terms of the Huntington's data for Ionis' antisense program partnered with Roche (RHHBY) presented today, Schimmer said there were "encouraging signs for some of the disease measures, less encouraging for others" along with "generally wide error bars." He has an Outperform rating on Ionis, which is down 11% to $45.06 in afternoon trading.