There was a lot of promise built into Anthera Pharmaceuticals' (Nasdaq: ANTH) stock price thanks to its late-stage experimental drug varespladib. The drug was aimed at treating short-term Acute Coronary Syndrome by targeting an enzyme that would reduce inflammation. Things appeared to be going well – until Friday.

Following the market close on Friday, Anthera released a statement that an independent review board had determined that, based on the data reviewed so far, it was unlikely that varespladib would work better than a placebo. Anthera has since discontinued its late-stage study and has recommended all patients be taken off the drug.

According to research done by Siemens, ACS was the leading cause of death in 2004, accounting for 12% of all deaths worldwide. Siemens estimates that $8 billion is spent annually on non-cardiac-origin hospital admissions that involve chest pain. Needless to say, the market for ACS-related drugs is huge.

In July 2011, AstraZeneca (NYSE: AZN) had its ACS treatment, Brilinta, approved by the FDA in the U.S. The drug is expected to bring in just north of $1 billion in revenue by 2016, according to Morningstar. Had Anthera's drug been approved, it would also have faced competition from Sanofi (NYSE: SNY) and Bristol-Myers Squibb's (NYSE: BMY) monster Plavix, the second-best-selling drug in the world, but which is set to lose patent protection worldwide. All of this is for naught now, though, with varespladib going back to the drawing board.

Now Anthera is going to be forced to rely on its phase 2 lupus drug, Blisibimod. Although lupus itself cannot be cured, we haven't exactly seen companies chomping at the bit in an attempt to solve the problem in decades. In fact, over the last 50 years, only Human Genome Sciences' (Nasdaq: HGSI) treatment Benlysta has gained approval, and even it hasn't exactly been selling like hotcakes, in large part because of the ebb-and-flow nature of the disease. Initial indications of Anthera's phase 1 trial looked promising, but as we've already seen, that doesn't necessarily mean much at this point.

Aside from other pre-clinical trials, Anthera has chosen to go it alone in many of its trials and now finds itself with a drastically reduced pipeline and just $93 million in cash left on its balance sheet. The absence of a phase 3 trial will help curb expenses, but it's quite possible that its cash may last only another two years without an equity offering or some sort of royalties from collaborating with a larger pharmaceutical company. For now I'm going to keep far, far away from Anthera, despite the stock price being halved overnight, and at least wait until we get phase 2 data on Blisibimod.

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