As the biopharma industry paused on Rare Disease Day to assess its progress and consider the plight of patients still waiting for therapeutic options, two players at opposite ends of the U.S. took the field in Duchenne muscular dystrophy (DMD). Boston-based Exonics Therapeutics Inc. is plying CRISPR/Cas9 gene editing technology with a goal of correcting the mutations that cause DMD and other neuromuscular diseases.