One of the major issues overshadowing RNA interference (RNAi) technology over the last year has been that it may do more harm than good. A study published last year found that when RNAi was performed in mice, they died. There was worry that the RNA molecules were interfering with normal cellular function in addition to doing what they're supposed to do -- inhibit the expression of specific genes.

Researchers at Alnylam (NASDAQ:ALNY), Roche, and three academic institutions have used a different approach that appears to lower the expression of specific genes by 80% -- without killing the mice. It appears that the problem wasn't an RNAi issue, but rather the way the inhibiting RNA was administered. The researchers in the most recent study used synthetic RNA molecules to inhibit the genes, rather than expressing the inhibiting RNA molecules inside the cell, as was done in the first study.

If you're thinking that all this talk about mice is a sign that RNAi technology is still in its infancy, you'd be right. My problem with RNAi isn't that it has no potential, but that companies are overpaying for an unproven technology. From Merck's (NYSE:MRK) purchase of Sirna Therapeutics to AstraZeneca's (NYSE:AZN) partnership with Silence Therapeutics to Novartis' (NYSE:NVS) and Roche's licensing of Alnylam's technology, big pharma has continued to pump hundreds of millions of dollars -- each -- into the technology. All I can say is, "At least it isn't killing mice anymore."

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Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. The Fool has a disclosure policy.