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 Receptos (NASDAQ:RCPT), a clinical-stage biopharmaceutical company focused on developing therapies to treat immune disorders, vaulted higher by as much as 27% after announcing the initiation of a phase 3 trial for RPC1063 for the treatment of relapsing multiple sclerosis.

So what: According to the company's press release, the independent data-monitoring committee reviewed data from the company's interim analysis of its phase 2 Radiance trial for RPC1063 and approved the continuation of the phase 2 portion of the trial and the initiation of a phase 3 portion. Although Receptos doesn't plan to release top-line data from the Radiance trial until mid-2014, it did release some key observations, including that its adverse-event profile appears to be consistent with medications already on the market and that it demonstrates a similar clinical benefit compared to other FDA-approved S1P receptor modulators.

Now what: Despite Biogen Idec bogarting the lion's share of the MS treatment market, there's plenty of room for Receptos' experimental compound to be successful if these results continue to be positive. As usual, though, I'd really like to see concrete data (i.e., the actual top-line report due out in mid-2014) rather than just "observations" before making my call -- so for now I'd be perfectly happy just sticking to the sidelines.

Fool contributor Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong.

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