After striking a deal a couple of years ago with Regulus Therapeutics, GlaxoSmithKline (NYSE: GSK) is back for more. Regulus, a joint venture between RNA powerhouses Alnylam Pharmaceuticals (Nasdaq: ALNY) and Isis Pharmaceuticals (Nasdaq: ISIS), announced yesterday that it had partnered with Glaxo to develop a drug to treat hepatitis C.

The deal is only worth $150 million, but then the potential drug hasn't hit the clinic yet. Adding to the risk, the drug targets a microRNA, which is a relatively new class of targets that haven't been proven in the clinic yet. It's a risky move for Glaxo, but at least it's not paying heavily for the privilege.

It's also a risky venture for Glaxo because the company doesn't know what the hepatitis C treatment landscape will look like in a few years. Roche and Merck (NYSE: MRK) sell the current treatments, but they only work in about half the people treated. There are plenty of new drugs further along than the one from Glaxo and Regulus, including ones from Merck and Vertex Pharmaceuticals (Nasdaq: VRTX), which will finish phase 3 trials this year, and Human Genome Sciences' (Nasdaq: HGSI) Albuferon, which has already completed its phase 3 trials.

None of those drugs is expected to cure all the patients, so there's still a need for additional treatments. But keep in mind that the current phase 1 and phase 2 drugs will be further along by the time Regulus' drug enters clinical trials next year, and so it's hard to say what the competition will look like by then. Perhaps the only advantage to coming in late is that Glaxo will be able to test the drugs in combination with the current phase 3 treatments, assuming they're approved by then.

Drug companies need to take a little risk and as long as they don't overpay, investors should be happy. Just don't pencil this one into the future-revenue column quite yet.

Tim Hanson says now's the time to buy risk.

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