Increase the Therapeutic Index of Antisense Oligonucleotides – Ther-ASO

Antisense oligonucleotides (ASO) therapy can be created for any patient, any target, including targets that have long been considered “un-druggable” by traditional therapies. In 2019, Ionis Pharmaceuticals, announced that more than 12,000 patients have been safety treated with ASO medicines across many disease areas. Even though these molecules are currently prescribed, their mechanisms of entry and action remain poorly understood. Moreover, the majority of diseases targeted by ASO requires recurrent ASO injections. Thus, ASO efficiency should be improved to reduce the amounts of delivered-ASO and their consecutive toxicities. We plan to 1) Identify the proteins involved in ASO uptake and ASO guidance to their RNA-targets using a genome wide approach (CRISPR activation of all coding genes), 2) Confirm the ASO-protein partners by ASO pull-down coupled to mass-spectroscopy, and 3) Improve ASO efficiency by modulating ASO-proteins interactions.
The originality of the project is based on three key elements. The proteins involved in ASO activity will be identified without any a priori using a genetic screen (CRISPRa) covering all coding genes. To maximize our chances of success, two complementary screens will be performed targeting two different RNAs (an endogenous RNA; TYRP1 and an exogenous RNA; Thymidine Kinase). The second advantage of this project is the use of different ASOs (mode of action and chemistry). This systematic study should highlight the specificities of interactions (ASO-proteins). The third strength of the project is related to the in vivo validation of our discoveries since the priority of the project is to improve the in vivo efficiency of ASOs in patients.

Beyond the elucidation of the molecular mechanism of ASO internalization and cell trafficking, identifying key ASO-protein partners can impact future ASO-biomedical applications through the design of novel ASO able to i) bind specific protein identified to favour ASO activity (as it was previously shown for nucleolin-specific aptamers or to ii) inhibit the binding to unfavourable proteins as it was shown for paraspeckle proteins associated with cellular toxicities.

The benefits for the community and the patients will be rapid because it is now conceivable to generate ASOs avoiding degradation pathways thanks to the addition of functional groups and thus increase their therapeutic effectiveness.
The complementary of the two teams involved and their expertise in different disease models (cancer and rare genetic disorders) and in various types of ASO reinforces the potential and feasibility of this project.
Since ASO therapy can be created for any patient, any target, including targets that have long been considered “un-druggable” by traditional therapies, this project aims at improving both ASO efficiency and tolerability, and consequently to reduce the cost of this therapy. The future of ASO will certainly be prodigious since ASO is tailor-made for diseases that have a genetic cause and corresponds to the epitome of precision medicine.