Duchenne muscular dystrophy (DMD) is caused by the lack of functional dystrophin protein. Improvements in patient care and disease management have slowed down disease progression, but current treatments cannot stop the relentless loss of muscle tissue and function, which leads to premature death. Research is ongoing to develop effective therapies for DMD. Gene-addition, exon-skipping, stop codon readthrough and genome-editing therapies can restore the expression of partially functional dystrophin protein, whereas other therapeutic approaches aim to improve muscle function and quality by targeting pathways involved in the pathogenesis of DMD. This Review outlines important developments in these research areas and specifically focuses on new therapies that are in the clinical trial phase or have already been approved.