COLLABORATIVE STUDY FINDS NOVEL RNAi TREATMENT FOR HUNTINGTON’S DISEASE
Pre-clinical results reveal effective and resilient therapeutic silencing of huntingtin, the gene responsible for Huntington’s Disease

October 30, 2007

WORCESTER, Mass.—Investigators from the University of Massachusetts Medical School, Massachusetts General Hospital in Boston, and Alnylam Pharmaceuticals, Inc. in Cambridge, have found a novel treatment for Huntington’s Disease, a debilitating, inherited neurodegenerative disorder, caused by the huntingtin gene, that affects approximately 30,000 people in the U.S.; another 150,000 are considered at risk for inheriting the illness from a parent with HD.  Research has revealed that the use of chemically synthesized small interfering RNAs (siRNAs), the molecules that mediate RNA interference (RNAi), silenced huntingtin and provided a therapeutic benefit. The findings appear in the current issue of the Proceedings of the National Academy of Sciences (PNAS).

In the preliminary study, researchers discovered that the RNAi therapeutic reduced the expression of mutant huntingtin and was well tolerated after direct administration into the central nervous system. The pre-clinical study demonstrated that siRNA, when injected, targeted huntingtin and improved disease symptoms, including reduction in neuronal pathology and prolonged and improved motor behavior. Huntington’s Disease causes neurological degeneration and is characterized by rapid, jerky body movements and the loss of normal mental abilities.

Encouraged by their recent study, the researchers believe these findings will contribute to promoting the advancement of RNAi therapeutics to treat patients with Huntington’s Disease. "I am excited by these new data as there is a very significant need for novel therapeutics to treat patients with Huntington's disease. Indeed, patients afflicted with this genetic disease are otherwise destined to an irreversible deterioration of neuronal function," said Neil Aronin, MD, professor of medicine, cell biology and physiology at the University of Massachusetts Medical School. "While more work is needed to advance this approach, the mechanism of action for RNAi therapeutics defines a promising therapeutic strategy that could slow or halt disease progression."

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About the University of Massachusetts Medical School
The University of Massachusetts Medical School is one of the fastest growing medical schools in the country, attracting more than $174 million in research funding annually.  A perennial top finisher in the annual US News & World Report ranking of primary care medical schools, UMMS comprises a medical school, graduate school of nursing, graduate school of biomedical sciences and an active research enterprise, and is a leader in health sciences education, research and public service.  In 1998, the UMMS system of hospitals and clinics merged with Memorial Health Care to form UMass Memorial Health Care, the clinical partner of the University of Massachusetts Medical School.

About Alnylam Pharmaceuticals
Alnylam is a biopharmaceutical company developing novel therapeutics based on RNA interference, or RNAi. The company is applying its therapeutic expertise in RNAi to address significant medical needs, many of which cannot effectively be addressed with small molecules or antibodies, the current major classes of drugs. Alnylam is leading the translation of RNAi as a new class of innovative medicines with peer-reviewed research efforts published in the world's top scientific journals including Nature, Nature Medicine, and Cell. The company is leveraging these capabilities to build a broad pipeline of RNAi therapeutics; its most advanced program is in Phase II human clinical trials for the treatment of respiratory syncytial virus (RSV) infection. In addition, the company is developing RNAi therapeutics for the treatment of influenza, hypercholesterolemia, and liver cancers, amongst other diseases. The company's leadership position in fundamental patents, technology, and know-how relating to RNAi has enabled it to form major alliances with leading companies including Medtronic, Novartis, Biogen Idec, and Roche. The company, founded in 2002, maintains headquarters in Cambridge, Massachusetts. For more information, visit www.alnylam.com.