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 Northwest Biotherapeutics (NWBO 4.54%), a predominantly development-stage biotech company engaged in the research of immunotherapeutic options to treat cancer, surged as much as 14% this morning following the announcement of the first case study in its DCVax-Direct trial for all types of inoperable solid tumors. The stock subsequently gave up nearly all of its gain and was up less than 1% as of this writing.

So what: According to Northwest Biotherapeutics, also known as NW Bio, "a sarcoma patient with a large tumor mass and multiple inoperable metastatic tumors in the lung" demonstrated via an MRI extensive necrosis and a partial collapse of the injected large tumor, while CT scans showed early indication of shrinkage in one of the noninjected metastasized tumors. NW Bio also noted that its findings were supported by tumor biopsies taken at the time of its latest DCVax-Direct injection (of which this patient has had three), which "showed a high rate of tumor necrosis and appearance of T cells (immune cells) infiltrating into the injected tumor." NW Bio concurrently announced that it would present further case studies at the annual American Society of Clinical Oncology meeting that begins on May 30.

Now what: While the data NW Bio shared with investors is encouraging, keep in mind that these are very early stage results, and DCVax-Direct's efficacy is being demonstrated in one very small handpicked snippet. That doesn't mean it won't work, it just means consider the bias of the data being presented today. NW Bio certainly has an exciting immunotherapeutic portfolio, but as with most immunotherapies I'd likely suggest waiting until we have the full data picture before breaking out the champagne, or running for the exit for that matter.