Casualties continue to accrue in Huntington’s disease, but drug developers continue their work in the challenging, fatal genetic disorder that afflicts an estimated 2.71 per 100,000 people globally. In March, Basel, Switzerland-based Roche Holding AG pulled the plug on its phase III Generation HD1 study with the antisense therapy tominersen, licensed from Ionis Pharmaceuticals Inc., of Carlsbad, Calif., in a tie-up that dates back to the spring of 2013. Roche subsidiary Genentech Inc. said the move was based on an independent data monitoring committee's preplanned look at the drug's risk-benefit profile.