Solid Biosciences Inc. already has its own Duchenne muscular dystrophy program, but with some new investment money it is plunging into a collaboration with Ultragenyx Pharmaceutical Inc. to co-create another program. The two will collaborate on developing and commercializing new gene therapies for treating Duchenne muscular dystrophy as Novato, Calif.-based Ultragenyx is investing $40 million in Solid.