ViroPharma (Nasdaq: VPHM) can finally step on the pedal. The biotech announced yesterday that the Food and Drug Administration approved the industrial-scale manufacturing of its hereditary angioedema treatment, Cinryze.

It's been a long time coming. Nearly two years ago, the FDA turned down ViroPharma's request to make the drug on a larger scale. The biotech was able to squeeze more product out of the smaller-scale production, but the company really needed the industrial scale to make sure there was sufficient stock.

With an approval in hand, it won't take long to get Cinryze into the supply channel. ViroPharma has already manufactured some of the drug at the newly approved scale and just needs to slap on new labels and it'll be able to ship it out. The biotech figures that will take about six weeks.

With supply no longer an issue, ViroPharma should be able to push sales harder than it has been. The biotech is scheduled to release earnings on Thursday, when investors will hopefully get more details on the company's plans.

Investors should also keep an ear out for news about ViroPharma's plans for a subcutaneous version of Cinryze. The FDA is concerned about the technology from ViroPharma's partner Halozyme Therapeutics (Nasdaq: HALO) that allows drugs to be injected under the skin rather than being infused. The FDA put a hold on clinical trials for the subcutaneous version of Cinryze and HyQ, which Halozyme is working on with Baxter (NYSE: BAX).

The subcutaneous version is more of a convenience issue, but may end up being very important to the long-term sales of the franchise. There's a lot of competition for hereditary angioedema patients with CSL's Berinert, Dyax's (Nasdaq: DYAX) Kalbitor, and Shire Pharmaceuticals' (Nasdaq: SHPG) Firazyr all approved to treat the disease, which causes swelling that can be life-threatening if it occurs around the airway.

For now, though, the chains are off the infused version, and investors will finally get to see how hard ViroPharma can push it.

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