In many cases, combining the knowledge from two different drug companies can spark innovation that couldn't happen in either of the companies alone. RNA interference (RNAi) rivals Alnylam Pharmaceuticals (NASDAQ:ALNY) and ISIS Pharmaceuticals (NASDAQ:ISIS) seem to understand that concept, and they have decided to join forces to bring a new technology to market.

The joint venture, called Regulus Therapeutics, will focus on the development of microRNA (miRNA) therapeutics. Both companies will contribute their intellectual property to Regulus, but because ISIS has more to give, Alnylam will make an initial investment of $10 million to balance venture ownership. After that, the two companies will share funding of the new company equally.

MicroRNAs are small, naturally occurring molecules that regulate genes in many organisms from plants to humans. The miRNAs bind to messenger RNA (mRNA) molecules and inhibit the expression of the genes. Scientists believe that a miRNA can control an entire pathway by down-regulating several genes in the pathway.

The molecules use the same mechanism of action as RNA interference, a technology that both companies are actively using to pursue therapeutics. But unlike the small interfering RNA (siRNA) used in RNAi, miRNAs are naturally occurring and therefore provide different options for their use as therapeutics.

Regulus will likely take two approaches in designing new drugs using miRNA technology. By designing inhibitors to miRNAs -- inhibiting the inhibitor -- the company could increase expression of genes needed to fight diseases. The company could also design drugs similar to naturally occurring miRNAs that would inhibit the expression of certain genes. That would be useful for treating diseases like cancer, in which up-regulated genes often promote the proliferation of the cells in the tumor.

The new company will compete against Rosetta Genomics (NASDAQ:ROSG), which IPOed earlier this year. The developmental-stage company is trying to take advantage of its miRNA-related IP and licenses from academic institutions to design diagnostic tests to determine the origin and severity of tumors. It's also trying to develop therapeutics based on its knowledge of miRNAs.

RNAi is a relatively new technology, and the discovery of miRNAs is even more recent. This new partnership will surely advance the scientific knowledge about miRNAs, but investors should be more worried about the companies developing novel drugs than about those pushing science forward. There are still major obstacles standing in the way of drugs being developed using RNA technology, but combining the two companies' forces should help them overcome those hurdles faster.

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Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. The Fool's disclosure policy inhibits the inhibitor of an inhibitor -- that is, it's quite positive.