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 OncoMed Pharmaceuticals (NASDAQ:OMED), a clinical-stage biopharmaceutical company focused on developing monoclonal antibodies to target cancer stem cells, gained as much as 12% after announcing a double-dose of mixed news late Friday and over the weekend.

So what: First, OncoMed announced that the Food and Drug Administration had placed investigational Wnt pathway drug vantictumab on partial clinical hold until it receives revised trial protocols that it agrees with. The move shouldn't come as a surprise given that OncoMed shares tumbled on Friday after announcing its voluntary clinical hold following instances of bone-related adverse events in eight of 63 patients in its study involving vantictumab.

Secondly, over the weekend OncoMed announced that it was presenting data for its notch 1 diagnostic assay at the European Hematology Association's annual meeting in Italy. Notch 1 mutations are often linked to refractory lymphoid malignancies, such as chronic lymphocytic leukemia and mantle cell lymphoma, but identification of the gene isn't easy. The idea is that notch 1 may prove a valuable biomarker which, when targeted early, could lead to more favorable patient outcomes.

Now what: OncoMed has now gained back all of Friday's tumble following the very early stage halt of vantictumab and Fzd8-Fc due to bone-related adverse events. Investors seem at ease with the understanding that partial clinical holds usually end up being lifted by the FDA once revised trial conditions are met, and that this is merely a temporary hurdle that OncoMed will have to overcome. In addition, investors may also be realizing that it's not worth getting all bent out of shape over two early phase studies when OncoMed has numerous other trials ongoing and a number of collaborative partners, complete with billions of dollars in possible milestone revenue.

I, for one, happen to be extremely intrigued by OncoMed's approach to targeting cancer stem cells as opposed to focusing on proliferating cancer cells like most other oncology-focused biotechs. I believe this could give the company an edge and is a reason why so many big pharma names have partnered with OncoMed. It's for that reason I'd suggest adding OncoMed to your watchlist and, for biotech-savvy investors, digging a bit deeper because you might like what you find.