Scientific American Hopes were high for drugs designed to lower levels of a mutant protein, but development has stalled orange Advertisement Two pharmaceutical companies have halted clinical trials of gene-targeting therapies for Huntington’s disease (HD), following the drugs’ disappointing performance. Researchers had hoped that the treatments—known as antisense oligonucleotides (ASOs)—would be a game changer for HD, an incurable genetic condition that affects cognition, behaviour and movement. But back-to-back announcements from Roche, headquartered in Basel, Switzerland, and Wave Life Sciences, in Cambridge, Massachusetts, have dealt a crushing blow to those affected by the disease. “I was really shocked, really tearful,” says Marion, a woman in London with HD, who was part of one of the trials. “We didn’t see it coming at all. I felt really frightened and worried about my future.” Marion requested that her last name be withheld to protect her privacy.