It didn't take long for Cardiome (Nasdaq: CRME) to erase some of the investor angst over having its lead drug, intravenous (IV) vernakalant, being stuck in an FDA black hole. Yesterday, Cardiome shares rose more than 30% after the company reported positive mid-stage data for an oral version of vernakalant.

The interim phase 2b study results Cardiome released yesterday showed that its oral version of vernakalant was effective at reducing the number of atrial fibrillation episodes (essentially, a type of irregular heartbeat) that patients experienced while on the drug for 90 days. Equally as good news for Cardiome, no major safety issues popped up in this interim look at the trial data.

What grabs investors' attention about oral vernakalant is that it's designed to be a chronically used compound, rather than the acutely used IV version of the drug whose FDA review has been delayed for two months now. The market for this oral version is thus much bigger, and Cardiome estimates that the potential market to be anywhere from $800 million to $3 billion annually, compared with the roughly $500 million in global sales opportunity for the IV formulation.

Cardiome has mentioned multiple times that it does not want to commercialize oral vernakalant on its own because of the huge costs of running a phase 3 program for such a drug. In conjunction with the positive interim data, Cardiome thus hired Merrill Lynch to help it sort out the various worldwide and U.S. partnering scenarios for the drug and also potentially its intravenous cousin (already partnered to Astellas in North America).

Final results from the phase 2b oral vernakalant study are expected around the third quarter of the year, so I doubt that there will be a partnership deal before then if Cardiome is looking to maximize the value it can get for the drug.

Cardiome's IV vernakalant was widely expected to receive marketing approval when its FDA review was scheduled to occur Jan. 19. Like the FDA has done for other drugs such as CV Therapeutics' (Nasdaq: CVTX) regadenoson, the agency has delayed approval for Cardiome's IV vernakalant for no explicable reason after singing the drug's praise in an advisory panel hearing. Cardiome mentioned yesterday that it had heard nothing from the FDA concerning the delay, but at least investors get to champ on this bit of good news about oral vernakalant while waiting to get the agency's approval of the IV formulation.

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Fool contributor Brian Lawler does not own shares of any company mentioned in this article. The Fool's disclosure policy is available in two versions -- paper and electronic.