Holly Kordasiewicz

Key facts

• Career: joined Ionis in 2011; BA SUNY Geneseo, PhD neuroscience University of Minnesota, postdoctoral work at Minnesota and UC San Diego, about eight years in the Cleveland lab on huntingtin-lowering ASOs.
• Other programs she is credited with: tofersen (SOD1 ALS, with Biogen) and the tau ASO BIIB080.
• Prion science: co-author of the 2019 JCI Insight paper on ASOs extending survival of prion-infected mice (prophylactic dosing 61 to 98 percent, a single injection near onset 55 percent) and of the 2020 Nucleic Acids Research paper showing PrP lowering works across stages and strains.
• Disclosure: listed as an Ionis employee in the AAN abstract on CSF PrP as a pharmacodynamic biomarker.
• Public statement on ION717 (October 2023, Ionis Innovation Day): ION717 has the potential to treat all forms of the disease, both presymptomatic carriers and symptomatic patients, with the goal of treating all patients; the first trial (PrProfile) was announced for symptomatic patients with no expanded access, developed by Ionis alone.
• Safety research interest: acute CNS tolerability of oligonucleotides, with two bioRxiv manuscripts in February 2025 on reversible sedation and neuronal activation after local delivery.
• Awards: 2019 Oligonucleotide Therapeutics Society Young Investigator Award.

Timeline

1. 2019JCI Insight paper on ASOs in prion-infected mice (co-author); OTS Young Investigator Award.
2. 2020Nucleic Acids Research paper on PrP lowering across stages (co-author).
3. 2023Ionis Innovation Day: ION717 and PrProfile named; her statement on treating all patients.
4. 2025Two bioRxiv manuscripts on acute CNS oligonucleotide tolerability list her as author per the society page (not opened).
5. 2025OTS member highlight published.
6. 2025Ionis announces her appointment as successor.