COPENHAGEN, DENMARK — Researchers report that a single injection of the microRNA AAV5-miHTT safely, effectively and sustainedly reduces levels of pathogenic huntingtin in minipigs up to five years post-treatment, according to an analysis of two studies released today at the International Congress of Parkinson’s Disease and Movement Disorders® in Copenhagen, Denmark.
MicroRNAs function by focally inhibiting gene expression – a desirable outcome when the subject’s DNA contains a mutated gene that produces a mutated, disease-causing protein. The anatomical injection location and gene therapy dosage were found to mildly influence the duration of therapeutic efficacy, but continued research will help optimize this promising treatment.
“The authors demonstrate the long-term safety and durability of an adeno-associated viral vector serotype 5 encoding an engineered miRNA (AAV5-miHTT) targeting human mutant huntingtin (mHTT) in the minipig animal model of Huntington’s disease (HD) up to 5 years post-injection,” Jennifer Goldman, MD, MS, expert movement disorder neurologist “This finding expands on their prior work revealing sustained cerebrospinal fluid (CSF) mHTT protein lowering up to 4 years after a one-time intrastriatal administration of AAV5-miHTT.”
“HD is an inherited neurodegenerative disorder for which we still seek a cure or disease-modifying treatment. As such, HTT-lowering strategies have received growing interest for their disease-modifying potential in HD clinical trials. AAV5 has been a candidate for RNAi-based gene transfer in HD animal models, and adeno-associated viral vectors have been recently studied in early-phase HD human trials, while others have been approved for neurologic diseases such as spinal muscle atrophy. The study illustrates an important sustained duration of effect on mHTT post-injection.
“In addition, the ability to deliver AAV5 intrathecally rather than directly via striatal delivery, coupled with demonstrated effects on mHTT in this abstract, may have promise for future human trials with therapeutic delivery via lumbar puncture infusion rather than neurosurgical stereotactical procedures.
“Whether changes in protein levels as measured in the brain, CSF or other biofluids are associated with suppression of aggregate formations, prevention of neuronal dysfunction, or importantly lead to clinical and behavioral changes and functional improvements remain to be seen. Understanding the effects of reduced mHTT and the targeted intervention on different brain regions will be important considerations in translating to human therapies. This research also adds to the literature regarding large animal models under study for HD such as minipigs, which may offer promise beyond rodent models for drug development. However, further development in these models regarding clinical features and behavioral tasks of HD may be needed.”
Full text of this abstract will be available at mdsabstracts.org (Reference #865) after the embargo lifts August 27, 2023, 08:00 CEST.
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About the 2023 MDS International Congress of Parkinson’s Disease and Movement Disorders®:
The MDS International Congress is the premiere annual event to advance the clinical and scientific discipline of Movement Disorders, including Parkinson’s disease. Convening thousands of leading clinicians, scientists and other health professionals from around the globe, the International Congress will introduce more than 1,800 scientific abstracts and provide a forum for education and collaboration on latest research findings and state-of-the-art treatment options.
About the International Parkinson and Movement Disorder Society:
The International Parkinson and Movement Disorder Society® (MDS), an international society of more than 11,000 clinicians, scientists, and other healthcare professionals, is dedicated to improving patient care through education and research. For more information about MDS, visit www.movementdisorders.org.