In July 2010, I wrote an analysis of the generic Taxotere (docetaxol) patent fight between Sanofi-Aventis (SNY) and the generics Hospira (HSP) and Apotex. In September that year, I reported that the District Court ruled in favor of Hospira and Apotex, finding that Sanofi's patents were invalid. I had predicted Hospira would jump on the news, and it did.
Today the Court of Appeals affirmed that verdict, agreeing with the District Court's rulings that the patents were invalid and also unenforceable due to inequitable conduct. The news hasn't seemed to move either stock, which isn't unexpected since Sanofi-Aventis had a very difficult task trying to get the District Court's ruling reversed.
The case isn't completely over just yet, though, as Sanofi-Aventis could seek Supreme Court review. However, that's extremely unlikely to be granted (the Supreme Court only takes about 1% of all cases it is asked to take and this one doesn't raise any issues of general importance). Therefore, I doubt this matter will have any future impact on the underlying company valuations.
Disclosure: I have no positions in any stocks mentioned, and no plans to initiate any positions within the next 72 hours.