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 Puma Biotechnology (NYSE:PBYI), a clinical-stage biopharmaceutical specialist focused on developing therapies to treat cancer, advanced as much as 19% after the company announced a positive outcome regarding patents claims held in Europe.

So what: According to Puma's press release, the European Patent Office upheld Puma's licensed European patent for the drug's use in treating cancer in patients with an EGFR mutation that expresses the T790M mutation. Privately held Boehringer Ingelheim had previously opposed Puma's claim of this patent, which Puma inherited when it licensed breast cancer drug neratinib from Pfizer in 2011. Although Puma won its day in Europe's patent court, it announced that it has no plans to develop neratinib to treat cancers with the T790M mutation.

Now what: In other words, "This patent is all ours, but we're not going to do anything with it at the moment." It's a bit difficult to understand why shares are up so much today based on a ruling that doesn't have a lot of bearing on neratinib's development. However, it's very clear why Puma has soared in recent months following its stellar midstage top-line results involving neratinib in combination with paclitaxel which delivered a Bayesian probability of superiority over the current standard of treatment of 94.7% in HER2-positive/HR-negative breast cancer. There's a lot of promise for neratinib, but unfortunately for investors on the outside looking in much of that promise has already been baked into Puma's share price.

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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