For those of you who are not familiar with RNA interference, here's what it is and how it works: DNA is, in a sense, the operating system software for our cells. As such, DNA does not directly interact with genes. It's too important to risk corruption through unnecessary exposure. Instead, DNA operates by sending out chemical instructions. These instructions are in the form of complex RNA molecules. They are similar to double-stranded DNA, but are usually single stranded.
Basically, these extraordinarily complex RNA molecules control gene activity or expression. This is important because nearly all diseases are either caused or cured by the proteins produced by genes. You can, therefore, think of the ability to increase or decrease the production of these proteins as an on/off switch for diseases.
The remarkably young science of RNA interference is based on the accidental discovery that it is possible to flip these switches. The remote control, so to speak, for these switches consists of portions of RNA molecules. Because these portions are recognized as invaders by the body, they provoke the rejection of larger disease causing RNA molecules. The other side of the coin is "RNA activation." This is the process that increases gene expression.
The birthday of the science, according to many, was in 1998. That was when an academic paper by Craig Mello and Andrew Fire was published. Based on RNA interference in a nematode worm, it won them the Nobel Prize in physiology or medicine in 2006.
RNAi companies, unlike stem cell firms, have grown very rapidly. Many have already been gobbled up and their value diluted in Big Pharma umbrella companies. This is not, by the way, because RNAi is further along. Nor is it because RNAi has more potential than regenerative medicine.
It is because RNAi was spared the legal and ethical concerns that stem cell companies had to deal with. Now the legal situation has been clarified and embryonic stem cells have been replaced for therapeutic uses by iPS and parthenogenetic cells. As a result, we can expect important stem cell companies to make similar deals.
Regardless, many RNAi companies already have significant capitalization and Big Pharma partnerships. Even at that stage of their development, however, they still have profound transformational potential. For example, I would have added RNAi pioneer Sirna Therapeutics to our portfolio. Sirna, however, was acquired in 2006 by Merck & Co. Inc. in a deal worth $1.1 billion.
That deal, the largest in the RNAi space so far, was followed by others:
Anglo-Swedish pharm firm AstraZeneca Intl. made a $400 million deal with a European RNAi firm Silence Therapeutics.
Alnylam formed a $1 billion partnership with Swiss giant Roche.
The high-water mark for RNAi stockholders, however, is still the Sirna Therapeutics acquisition by Merck in October 2006.
As I've written before, RNA interfering molecules work. There is no question that they flip the switches they're supposed to flip. The challenge, however, is getting them to their target genes before they are recognized and destroyed by the body's immune system. Various companies are homing in on specific delivery solutions now. There are, however, many different solutions to the delivery problem. Each gene switch has its own special considerations and there is no "one size fits all" solution.
Most of the new RNAi companies have been founded specifically to develop RNAi therapies. One of our picks, however, found itself with special insight into the challenges of drug delivery even before Big Pharma began buying RNAi startups.
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