Study May Enable Huntington’s Treatment Tracking

Harvard researchers have identified a biomarker for Huntington’s Disease, a discovery that may allow physicians to track the effectiveness of treatments and the progression of the neurodegenerative, genetically dominant disease.

The study, published online last week in the Proceedings of the National Academy of Sciences, found that Huntington’s patients express the biomarker H2AFY 1.6 times as much as people without the disease.

The project, a collaboration between Harvard Medical School faculty Clemens R. Scherzer and Steven M. Hersch, identified many possible biomarkers for Huntington’s, but decided to use H2AFY, a transcriptional biomarker that can be measured with a blood test. This biomarker was isolated by testing blood samples of patients who were healthy, had Huntington’s, or had another neurodegenerative disease. These patient categories allowed the researchers to disentangle biomarkers associated with all neurodegenerative diseases from those specific to Huntington’s. In testing on mice and in a two-year study on Huntington’s patients, a correlation was found between the rise in the H2AFY biomarker and the onset and worsening of the disease.

There is no known cure for Huntington’s disease, and it is very difficult to track the success of treatments because the disease is highly variable and progresses slowly.

Phase II medication trials—involving studies of 60-70 patients for about six months—are often inconclusive. Researchers must rely on phase III trials, which are much more expensive and track hundreds of patients over a number of years.

“The problem is that the current clinical trial design is very inefficient,” Scherzer said.

Scherzer added that there is currently no medication that can slow the disease process. Physicians can only provide treatments that alleviate the symptoms of the disease, which Scherzer appear when patients are in their 30s and 40s, and include jerking movements, depression, behavioral problems, unsteady gait, and slow degradation of the mind that results in dementia.

“There are many aspects of the disease that one can intervene in and help people with, even as they decline over time,” Hersch said. In addition to his research, Hersch also treats Huntington patients clinically, addressing each symptom individually with physical therapy and medication.

Hersch said the researchers’ next step is to test this biomarker in a large-scale three-year longitudinal study performed by the Huntington Study Group. While that goes on, Hersch and Scherzer will continue to improve and refine their biomarker test, and continue to develop a “toolbox” made of “a suite of biomarkers” in conjunction with neuroimaging that may facilitate reliable drug testing at the phase II level.

Scherzer hopes that one day, he can achieve his “holy grail,” which would be to convert this research into a test similar to that for “cholesterol level,” in which Huntington’s can be monitored and treated according to test results.

—Staff writer Joseph E. Glynias can be reached at jglynias@college.harvard.edu.