Therapeutic advances in Huntington's Disease

Huntington's disease is a rare hereditary degenerative disease with a wide variety of symptoms that encompass movement, cognition, and behavior. The genetic mutation that causes the disease has been known for more than 20 y, and animal models have illuminated a host of intracellular derangements that occur downstream of protein translation. A number of clinical trials targeting these metabolic consequences have failed to produce a single effective therapy, although clinical trials continue. New strategies targeting the protein at the level of transcription, translation, and posttranslational modification and aggregation engender new hope that a successful strategy will emerge, but there is much work ahead. Some of the clinical manifestations of the illness, particularly chorea, affective symptoms, and irritability, are amenable to palliative strategies, but physicians have a poor evidence base on which to select the best agents. Clinical trials since 2013 have dashed hopes that coenzyme Q10 or creatine might have disease-modifying properties but suggested other agents were safe or hinted at efficacy (cysteamine, selisistat, hydroxyquinoline) and could proceed into later-stage disease modification trials. The hunt for effective symptom relief suggested that pridopidine might be shown effective given the right outcome measure. This review summarizes recent progress in HD and highlights promising new strategies for slowing disease progression and relieving suffering in HD.