Authors :
Nikolaos Giagtzoglou, PhD - Camp4 Tx; Olga Okhorkova Okhorkova, PhD - N/A; Chris Brynczka, PhD, DABT - Camp4 Tx; Rachana Kelkar, MSc - Camp4 Tx; Yeliz Yuva-Aydemir, PhD - Camp4 Tx; Cynthia Smith, BS - Camp4 Tx; Ali Al Abduallatif, MSc - Camp4 Tx; Evan cohick, BS - Camp4 Tx; Yuting Liu, PhD - Camp4 Tx; Gokul Ramaswami, PhD - Camp4 Tx; Bryan Matthews, PhD - Camp4 Tx; Brian Schwartz, PhD - Camp4 Tx; Claes Wahlestedt, MD - University of Miami, Miller School of Medicine; David Bumcrot, PhD - Camp4 Tx; Alfica Sehgal, PhD - Camp4 Tx
Rationale: Regulatory RNAs (regRNAs), including enhancer RNAs, promoter-associated RNAs and Natural Antisense Transcripts (NAT) are key regulators of mRNA transcription
1,2. We have developed an RNA Actuating Platform (RAP
TM) that enables modulation of gene expression by targeting regulatory RNAs (regRNAs) with antisense oligonucleotides. Here, we present our progress towards developing an antisense oligonucleotide (ASO) targeting the SCN1ANAT as a therapeutic for Dravet Syndrome._x000D_
Methods: Antisense Oligonucleotides targeting SCN1A NAT were evaluated
in vitro in SK-N-AS cells and Dravet patient derived fibroblasts as well as
in vivo in non human primate animals. The abundance of SK-N-AS mRNA and NAT was then evaluated by a multipronged experimental approach.
Results: The majority of Dravet syndrome patients are haploinsufficient for SCN1A. Our therapeutic strategy is to increase the expression of the wild-type allele to restore function. As previously shown
3, we identified ASOs that target human and mouse SCN1ANAT leading to increased SCN1A mRNA expression in cultured cells, including fibroblasts derived from Dravet patients. Epigenomic analyses in cultured human cells are in progress to define the mechanism whereby NAT targeting increases SCN1A expression.
In a mouse Dravet Syndrome model, ASO treatment led to an increase of SCN1a expression in the brain. This was accompanied by an approximately 70% decrease in the number, frequency, amplitude and duration of seizures. This robust efficacy supports the advancement of a SCN1ANAT-targeting assay as a therapeutic approach for Dravet Syndrome. Towards that end, we are conducting exploratory pharmacokinetic studies in non-human primates. These studies will inform the design of IND-enabling GLP tox studies with our lead ASO targeting human SCN1ANAT.
Conclusions: We have shown that ASO targeting of SCN1ANAT is a viable therapeutic approach for Dravet Syndrome, and we are advancing a lead ASO into clinical testing.
Given the generality of this mechanism, it is likely that this approach can be applied to a range of haploinsufficient diseases, including other genetic epilepsies._x000D_
References
1. Li, W., Notani, D. & Rosenfeld, M. G. Enhancers as non-coding RNA transcription units: recent insights and future perspectives. Nature Reviews Genetics 17, 207–223 (2016).
2. Wahlestedt, C. Targeting long non-coding RNA to therapeutically upregulate gene expression. Nat Rev Drug Discov 12, 433–446 (2013).
3. Hsiao, J. et al. Upregulation of Haploinsufficient Gene Expression in the Brain by Targeting a Long Non-coding RNA Improves Seizure Phenotype in a Model of Dravet Syndrome. EBioMedicine 9, 257–277 (2016).
Funding: Please list any funding that was received in support of this abstract.: Private Investors:_x000D_
_x000D_
Polaris Partners_x000D_
Andreessen Horowitz_x000D_
5AM Ventures_x000D_
Northpond Ventures_x000D_
Alexandria_x000D_
The Kraft Group