Arcturus Therapeutics


RNA interference (RNAi) is a natural mechanism used by the body to turn off genes without permanently changing DNA. It controls how and when genes are turned into proteins and is part of the innate immune response to viruses. RNAi occurs when a small RNA (a microRNA, small interfering RNA, or antisense RNA) binds to messenger RNA (mRNA) and stops a cell from turning that mRNA into a protein product.

RNAi medicines can turn off any gene in the genome, treating diseases caused by too much protein or by defective proteins. RNAi therapeutics can also target viruses and prevent them from replicating.

RNAs are unstable molecules that rapidly degrade in the gut or bloodstream. Our patented LUNAR delivery system can protect RNA medicines and safely deliver them to target cells. Our proprietary UNA oligomer technology can be used to develop more potent and effective RNAi therapeutic compounds.



Small interfering RNA (siRNA) medicines can treat viral infections like hepatitis B and inherited diseases caused by malfunctioning proteins such as transthyretin-mediated amyloidosis (ATTR). Each siRNA binds perfectly to one messenger RNA (mRNA) and tells machinery in the cell to destroy that mRNA. This mechanism, called RNA interference, or RNAi, can be used to prevent mutated genes from being translated into defective disease-causing proteins. It can also stop viruses from replicating inside the body.

Our LUNAR lipid-mediated delivery system and UNA oligomer technology can be used to make safer, more effective siRNA medicines. Synthetic siRNA medicines can stimulate an adverse immune response. Our LUNAR technology can prevent this by delivering siRNAs directly into target cells. siRNA medicines can sometimes bind imperfectly to unintended mRNA targets. Adding UNAs into the siRNA sequence can prevent these off-target side effects.

We have partnered with a number of industry leaders to develop novel siRNA drug candidates using our LUNAR and UNA technology platforms.



MicroRNA medicines can be used to treat complex diseases like cancer that are caused by many different malfunctioning genes and proteins.

MicroRNAs are small RNAs that naturally occur in humans, and many other animals, and regulate how much protein is made from messenger RNA (mRNA). Each microRNA can target hundreds of different mRNAs and so can regulate entire networks of genes.

MicroRNAs are one of several classes of small RNA molecules involved in a mechanism called RNA interference or RNAi. MicroRNAs, small interfering RNAs and antisense RNAs can all bind to mRNA and prevent it from being translated into protein.

However, unlike other small RNAs, microRNAs can also work to increase the amount of protein made from mRNA. This means that microRNA medicines can be used to treat diseases like cancer that have too much of some proteins but too little of others.

Our proprietary LUNAR delivery system can safely deliver microRNA medicines directly to clinically important target cells.


Antisense Oligonucleotides

Antisense RNA medicines can treat diseases like Duchenne muscular dystrophy that are caused by excess or defective proteins.

Antisense RNA works by binding to messenger RNA (mRNA) and physically preventing the cell from translating the mRNA into protein. When antisense RNA binds to mRNA, it also signals the cell to destroy the mRNA. These mechanisms are called RNA interference, or RNAi, because they stop the protein product of a particular gene from being produced. Each antisense RNA targets and inhibits one specific mRNA.

One of the biggest challenges when developing RNA medicines is delivering the therapeutic RNA into cells. All types of antisense RNAs can be safely delivered to target cells with our LUNAR delivery platform. Antisense RNAs are quickly degraded inside cells, so medicines based on this type of RNA can have low potency and efficiency without our protective LUNAR lipid-mediated delivery system.

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