Ionis Pharmaceuticals, Inc. (formerly Isis Pharmaceuticals, Inc.) announced today that it has launched a Phase 1 clinical trial for IONIS-DMPKRX. IONIS-DMPKRX is designed to reduce the production of toxic dystrophia myotonic-protein kinase (DMPK) RNA in cells, including muscle cells, for the treatment of Myotonic Dystrophy Type 1 (DM1).