Why OncoMed Pharmaceuticals, Inc. Shares Temporarily Spiked Higher

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 (OMED), a clinical-stage developer of cancer therapy agents that target cancer stem cells, jumped as much as 18% after presenting data from its phase 1b studies involving demcizumab and OMP-59R5 for advanced pancreatic cancer at the 2014 Gastrointestinal Cancers Symposium. Shares have since given up most of their gains and are now up less than 4% as of this writing.

So what: According to OncoMed's dual press releases, the phase 1b trial involving its lead compound, demcizumab, and co-administered with Eli Lilly's (LLY -1.81%) Gemzar and Celgene's (CELG) Abraxane, demonstrated a RECIST partial response in three of six patients with stable disease noted in two others for a clinical benefit rate of 83%. The combination therapy was considered well tolerated in this initial study and a mid-stage study is planned for the second half of the year. With regard to OMP-59R5, OncoMed notes similar success in combination with Gemzar and Abraxane with good tolerability of the drug combo. Of the 13 patients treated with this combination, six achieved a RECIST partial response with three additional patients demonstrating stable disease. Like the previous trial, a mid-stage study is planned for the second half of the year.

Now what: The past two months have been nothing short of perfect for OncoMed shareholders, with the company striking what could be a multibillion-dollar drug development pact with Celgene and now reporting initially encouraging early-stage data. The reason shares have backed off during the day likely has to do with the company's already-incredible run following its Celgene collaboration announcement and the fact that we're dealing with very early data here. Give these two therapies time to develop and the market may reward them with a higher valuation as there is a huge market for improved pancreatic cancer therapies.