Merck's (NYSE: MRK) Victrelis and Vertex Pharmaceuticals' (Nasdaq: VRTX) Incivek have been on the market for only five months, and the threats to unseat them keep coming.

Data on some of the next-generation hepatitis C drugs will be presented at the end of this week, when the annual meeting of the American Association for the Study of Liver Diseases kicks off. Add in top-line data that's been released recently and expected results in the next few months, and the hepatitis C space is looks like it'll get really crowded, really quickly.

The biotech front-runner
Pharmasset (Nasdaq: VRUS) has grabbed most of the spotlight. The company has a drug, RG7128, partnered with Roche, but most of the focus has been on PSI-7977 that it owns in its entirety. The company will present data at the meeting including results using PSI-7977 as a monotherapy. Reducing or eliminating peginterferon, which must be used with Incivek and Victrelis, is a goal of every next-generation hepatitis C regimen because of nasty side effects with peginterferon.

Achillion Pharmaceuticals (Nasdaq: ACHN) will make multiple presentations at the meeting, with its phase 2 compound, ACH-1625, being the most interesting. Idenix Pharmaceuticals has a pair of presentations at the meeting.

No shortage of pharma competition
Unfortunately for the smaller biotechs, Big Brother is interested in the space as well.

Earlier this month, Abbott Labs (NYSE: ABT) said it has a drug combination that might be able to deliver cure rates as high as 90% without peginterferon. Don't write off the others just yet, though. It was a fairly small trial, and the data from more patients might not be as impressive.

Bristol-Myers Squibb (NYSE: BMY) recently presented data for one of its compounds, BMS-790052. In a phase 2 trial, 83% of patients taking the two highest doses of BMS-790052 had undetectable viral levels 24 weeks after treatment, compared with just 25% who took just peginterferon alfa and ribavirin. But the results with BMS-790052 required adding it to peginterferon and ribavirin.

The upside to pharma's interest
Fortunately for biotechs, combination treatments are likely to be key to ridding patients of the virus. Resistance issues are common, but they can be avoided by combining medications that attack the virus in different ways.

No doubt Roche's acquisition of Anadys earlier this month was driven by its desire to get a hold of Anadys' hepatitis C treatment, setrobuvir. While we might see more acquisitions in the works, partnerships -- especially non-exclusive ones -- could be the best solution for both sides. Pharmasset has used the double-dipping strategy making pacts with both Johnson & Johnson (NYSE: JNJ) and Bristol-Myers to combine their hepatitis C treatments with PSI-7977.

The problem with non-exclusive pacts is that they may not provide biotechs with much cash to fund their own development. On the other hand, if a biotech doesn't make too many of them, it could lead to a takeout offer.

Which combo is the combo?
It's hard to know which combination will eventually win out. When you start adding multiple drugs to each other, there's bound to be side-effect issues that aren't a problem when they're used individually. Hepatitis C is a little less life-threatening than HIV, so the FDA will demand a cleaner side-effect profile than they have for cocktails that treat HIV.

And while finding the most potent combination is important, it's useful only if they complement each other's resistance issues; knocking the virus down to undetectable levels in 100% of the patients isn't particularly useful if the virus just rebounds once it mutates in a way to avoid the drugs' inhibitory properties.

Rather than trying to guess which company will eventually profit, buying a basket of hepatitis C drugmakers might be the best move. If a combo treatment is going to eventually work, why not a combination of investments?

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