Isis Pharmaceuticals awarded $1.5 million NIH grant to improve RNAi-based therapeutics

Isis Pharmaceuticals, Inc. has announced that it has been awarded a multi-year Phase 2 Small Business Innovation Research (SBIR) grant by the National Institutes of Health (NIH) for up to $1.5 million to design oligonucleotide drugs that can exploit the RNA interference (RNAi) antisense mechanism for disease treatment.

The Phase 2 grant builds upon a successfully completed Phase 1 program that demonstrated the feasibility of using single-stranded antisense drugs to target the RNAi pathway.

"We are pleased with the continued support from the NIH in our ongoing efforts to apply our RNA technologies, oligonucleotide chemistries and expertise to exploit antisense mechanisms, such as RNAi, for therapeutic benefit. Based on our extensive work with single-stranded antisense drugs that work through an RNase H mechanism and the feasibility studies we have completed with single-stranded antisense drugs that harness the RNAi pathway, we are optimistic that the two drug families will share certain characteristics, including bioavailability and tissue distribution," said C. Frank Bennett, PhD, Senior Vice President of Research at Isis Pharmaceuticals, Inc. "At Isis, we have a rich history of pioneering work in RNA-targeted drug discovery, and with this research we are continuing to expand the ways in which we can harness biological phenomena with compounds exhibiting chemical properties that enable development of practical, safe and attractive drugs."

The multi-year grant will fund research by Isis to improve the stability and tissue distribution of RNAi drugs. Much of the work will focus on optimizing the chemical properties of single-stranded oligonucleotides that trigger the RNAi pathway. In addition to demonstrating that compounds optimized with Isis' chemistries produce superior results in animal models when compared to unoptimized compounds, the grant funds the discovery of RNAi-based drugs.

RNAi is an antisense mechanism that involves using RNA to target a specific messenger RNA sequence (mRNA) for degradation. The most common RNAi agents are double-stranded RNAs, which ultimately associate with proteins to form an RNA-induced silencing complex (RISC). The antisense RNA within active RISC binds to its mRNA target, which is then cleaved and degraded by the RNase enzyme in the complex. Although most currently practiced methods of inducing the RNAi mechanism utilize double-stranded RNAs, RISC requires only the antisense strand to function. This provides the opportunity to develop simplified single-stranded antisense drugs that can utilize the RNAi pathway to treat human disease.