Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of clinical-stage biopharma Sarepta Therapeutics (NASDAQ:SRPT) rose by nearly 15% in early morning trading today on heavy volume, following an upgrade from analysts at Bank of America/Merrill Lynch. In the note to investors, the firm modestly upped its outlook, from a 40% to 50% chance, that Sarepta's experimental Duchenne muscular dystrophy treatment, eteplirsen, will ultimately be approved by the Food and Drug Administration.

So what: Sarepta shares have lost roughly half of their value in the last year because of a series of regulatory setbacks for eteplirsen. So while today's upgrade and analyst commentary aren't exactly an overwhelming vote of confidence, it might help to stem the stock's downward spiral. 

Now what: Sarepta and the FDA have been engaged in a vigorous debate over the drug's regulatory pathway for well over a year now, with the company pushing for an accelerated approval based on a small mid-stage study, coupled with an ongoing follow-up study.

The FDA, though, has questioned some of the study's most promising results, and are now requiring an independent assessment of the data prior to a formal regulatory review. The company hopes to have these additional roadblocks cleared by mid-2015, putting a regulatory decision on track for early 2016. 

If Sarepta is successful in gaining an approval sooner rather than later, it's important to keep in mind that it would be a 'conditional' approval, pending the outcome of a large late-stage trial. Put simply, this speculative biotech has a number of major hurdles to overcome moving forward, many of which will take years to fully resolve. Ultimately, I'd say this stock might be a good one to shy away from for the time being.