Ionis Pharmaceuticals Inc. announced that Roche has enrolled the first patient in a pivotal study of RG6042 (IONIS-HTTRx) for people living with symptoms of Huntington's disease (HD), a hereditary neurodegenerative disorder for which there is currently no approved disease-modifying treatment. RG6042 is the first therapy in pivotal trials designed to target the underlying cause of HD by reducing production of the toxic mutant huntingtin protein (mHTT).