On a day when the Dow Jones Industrial Average (INDEX: ^DJI) closed up 101 points as the European debt drama continues to unfold, significantly larger moves happened in the health-care sector. Let's find out which stocks were today's big movers and big newsmakers.

Opexa Therapeutics (Nasdaq: OPXA) investors are 33% richer this evening as the FDA granted its multiple sclerosis drug Tovaxin fast-track approval. Tovaxin tackles the secondary progressive form of MS, for which currently there are no good treatment options. Fast-track approval combined with an unmet need should bolster the small biotech's chances at approval. But investors need to remember that without ever having made a dollar in revenue, this is a one-trick pony with significant risk remaining despite today's good news.

Of course, it could be worse, as Targacept (Nasdaq: TRGT) investors found out. Shares plunged a whopping 60% as experimental depression drug TC-5214 failed to meet its efficacy goal in a phase 3 trial. This is what can happen when investing in one-trick ponies. For instance, Targacept's partner is diversified pharma giant AstraZeneca (NYSE: AZN), which closed down only 1%. Hope isn't totally lost, though, as depression treatments need only to show that they work in two of four trials, and results from the other three parts are expected by June 2012. That said, investors must be nervous thinking that they're watching a redux of the duo's Alzheimer struggles.

Break-ups are hardly ever mutual, even if both parties involved claim different. And while Amylin Pharmaceuticals (Nasdaq: AMLN) can insist otherwise, shareholders knew better. The termination of its partnership with Eli Lilly (NYSE: LLY) sent shares down 11% today. The key product is diabetes treatment Byetta and, more importantly, the once-weekly version called Bydureon that still has to get FDA approval. The real challenge to Bydureon may not be stealing market share from Novo Nordisk's (NYSE: NVO) Victoza itself a daily injection, or Merck's oral Januvia, but linagliptin, a direct competitor Lilly is working on. That drug created bad blood between the two companies that ultimately led to the split. Amylin will have to pay Lilly 15% royalties up to $1.2 billion, but if Bydureon becomes a blockbuster, Amylin will be happy to write those checks.

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