Bicyclic oxazaphospholidine (OAP) monomers were used to prepare a series of phosphorothioate (PS)-modified gapmer antisense oligonucleotides (ASOs) targeting Malat-1 or Lrrk2 mRNA.  We found that controlling PS chirality in the MOE wings or in the DNA gap did not enhance ASO potency or duration of effect in the CNS relative to their stereo-random counterparts. Complete details, including sequence, design of ASOs and lessons learned, will be presented.

Wave Life Sciences has developed PRISM^TM, our proprietary discovery and drug development platform, which enables us to generate stereopure oligonucleotides to target genetically defined diseases. Stereopure oligonucleotides are those in which the chiral configuration of backbone-modified oligonucleotides is precisely controlled at each linkage. We have demonstrated that, in addition to sequence and other chemical modifications, control over backbone stereochemistry provides an important new dimension for the optimization of oligonucleotide therapeutics. PRISM combines our unique ability to construct stereopure oligonucleotides with a growing knowledge of how the interplay among oligonucleotide sequence, chemistry and backbone stereochemistry impacts key pharmacologic properties. Using PRISM, we optimize stereopure oligonucleotides to meet pre-defined product profiles. We illustrate by example that optimized, stereopure oligonucleotides exhibit the desired activity across multiple modalities, for example those that depend on RNase H and those that promote exon skipping. We demonstrate that the potencies of stereopure oligonucleotides in cellular models under free-uptake conditions help predict their potencies in animal models. We also show that stereopure oligonucleotides can potently engage and durably impact the expression of their targets in animal models.

The aim of the antisense-mediated exon skipping therapy is to allow Duchenne patients to produce Becker-like dystrophins, hoping this will slow down disease progression. Antisense oligonucleotides (ASOs) will hide a target exon from the machinery, preventing its inclusion into mRNA. This restores the reading frame, allowing the production of a partially functional dystrophin, as found in Becker muscular dystrophy patients. Currently, one exon skipping ASO has been approved for Duchenne therapy by the Food and Drug Administration, while another was not approved. The presentation will outline the development of this approach through proof-of-concept studies in cell and animal models, preclinical optimization studies and clinical trials, but will also discuss the required multilateral education of stakeholders (patients, regulators and academics) to develop tools to measure clinical efficacy of the approach.

Advances in platform technology as well as proof of concept data from non-clinical and clinical studies in ocular indications will be discussed.

The ZON platform is a novel class of oligonucleotides synthesized via phosphoramidite chemistry that permits facile attachment to the internucleoside phosphate charge-neutralizing groups (CNG), bearing positive charges at their termini. ZONs have length-optimized CNG branches, allowing these positive charges to reach their neighboring phosphate groups where they can neutralize negative charges. ZON technology can be equally applied to DNA and RNA derivatives and be applied in all oligotherapy approaches.

We developed a divalent (Di)-siRNA scaffold that supports potent and sustained gene silencing in the CNS upon intra-cerebroventricular (ICV) injection. Di-siRNAs are stabilized by 2’ modifications on every ribose, phosphorothioate backbone modifications, and substitution of the 5’ phosphate with metabolically stable 5’-(E)-vinyl phosphonate. In mice, di-siRNA silences target mRNA in mouse CNS for at least 6 months without detectable toxicity. In cynomologus macaques, a bolus injection of di-siRNA showed substantial distribution and robust silencing throughout CNS without detectable toxicity and minimal off-target effect.

In this presentation, we will demonstrate the impact of mobile phase optimization on chromatographic separation and MS sensitivity and spectral quality. Additionally, we will look into how temperature and flow-rate can impact oligo separations as well.

OliX pharmaceuticals is developing novel RNAi therapeutics against a variety of diseases with unmet medical needs, based on its proprietary asymmetric siRNA (asiRNA) platform. In this presentation, we will introduce preclinical data from OLX301A and 301D, ocular asiRNA therapeutic programs targeting age-related macular degeneration (AMD).

RNA interference can be a potent regulatory mechanism in human cells. Synthetic RNAs can control gene expression and have been developed to be successful drugs while endogenous miRNAs can control natural physiologic processes and disease. Despite two decades of study, however, the full scope of natural RNAi in cells has remained obscure. Our results suggest that the action of miRNAs in cells is complex and must be justified with care.

Using a proprietary and optimized polypeptide nanoparticle (PNP) -based delivery technology, we have developed the novel anti-fibrosis and anti-cancer therapeutics with siRNAs targeting both TGFβ1 and Cox-2 simultaneously (STP705), resulting in human fibroblasts apoptosis. STP705 was initially used for local treatments for skin hypertrophic scar and non-melanoma skin cancer. STP707 (a systemic formulation of STP705) was further advanced for treatment of liver fibrosis and cholangiocarcinoma, both of these indications have received Orphan drug designations by US FDA. I will discuss the unique advantage using our PNP technology platform for safe and efficient siRNA delivery, and our strategy for advancing multiple clinical studies ongoing in both USA and China.