St. Louis patent litigator Doug Robinson contributed his thoughts to a recent Law360 article that discusses a new analysis of patent challenges to approved drug products.

Since the AIA went into effect, companies looking to make generic drugs have been quick to file challenges against owners of biopharmaceutical patents via the Patent Trial and Appeal Board (PTAB). Common wisdom dictated that patents were easier to invalidate at PTAB rather than district court.

This recent study, however, asserts that 23% of PTAB decisions involving Orange Book patents invalidated all challenged claims, whereas 24% of district court proceedings invalidated all challenged claims — thereby giving the edge to district courts for having a higher patent invalidation rate.

The study also points out that not all technology areas within drug patents have the same invalidation rates. For example, the study found zero compound patents — patents directed to an active ingredient — that were invalidated at the PTAB and only two that were invalidated at district court.

“The courts are loathe to invalidate a compound based on another compound because of the inherent unpredictability of chemistry,” said Robinson.

Another factor may be the success of drug products covered by these patents. “The idea there is that if something is obvious, there is plenty of incentive to try to commercialize it in a pharmaceutical setting,” he added.

Overall, the pharma industry may have been slow to adopt AIA reviews as a strategy, but the number of PTAB cases involving drug patents is now on the rise. Challengers can expect to encounter savvy patent owners who rely on the unpredictable nature of chemistry to defend their claims or find other arguments to attack challengers’ evidence.

Patent owners, on the other hand, are unlikely to see much change in the number of Paragraph IV certifications based on this data.

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