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ION581

Generation 2+ antisense drug

ION581 is an antisense oligonucleotide (ASO) that targets Ubiquitin Protein Ligase E3A-Antisense Transcript (UBE3A-ATS), which is a long non-coding ribonucleic acid (lncRNA). ION581 reduces the levels of UBE3A-ATS and is being developed as a potential therapy for Angelman Syndrome (AS). Angelman Syndrome is caused by maternal deficiency of the Ubiquitin Protein Ligase E3A (UBE3A). The paternal copy of the UBE3A gene is usually intact but is silenced by the UBE3A-ATS. It has been shown in iPSC neurons derived from AS patients and in an AS mouse model that ASO-mediated suppression of UBE3A-ATS results in UBE3A unsilencing and robust expression from the paternal allele. ASO-mediated up-regulation of UBE3A mRNA has the potential to restore the levels of UBE3A protein in neurons in patients with AS.

About Angelman syndrome

Angelman syndrome is a rare neurogenetic disorder caused by the loss of function of the maternally inherited UBE3A gene and affects approximately 1 in 15,000 individuals. Angelman syndrome presents early in life with profound and severe developmental delays in motor, language and cognitive functioning, seizures and ataxia. It is a non-degenerative, life-long disorder that generally remains clinically unchanged, resulting in complete dependence on a caregiver throughout their life. Some symptoms can be managed with existing drugs; however, there is no disease modifying therapy.