Cheeky Apotex was briefly selling a generic version of blood clot preventer Plavix®, which is still under patent protection for holder Sanofi. Apotex was making money hand over fist for a few weeks in August, until a preliminary injunction shut it down. Apotex is appealing, arguing invalidity, and of all things, irreparable harm. Trial is set for January.

The money involved is too great for generic firms not to roll the dice in an infringement showdown. Eli Lily is wrestling with attacks on its patents for Prozac®, Evista®, and Zyprexa®. Pfizer, with the world's best selling drug, cholesterol-reducing Lipitor®, frequently fends off challenges from generics.

As the Economist reports, "curiously, rather than using the law to defend their patents, big firms often settle out of court." One perceived reason is "as a way to bribe a generics firm to delay its introduction of a cut-price product." But that leaves the why? question in the breeze.

As seen in the Ditropan® case, the answer may be: junk patents. Drug patents are most often incremental improvements. Even a firm convinced of its patent's validity may settle as a way to avoid a bone-chilling confrontation in court. With the CAFC having opened the floodgates for successful challenges for obviousness combinations, the days may be numbered for numerous blockbuster drugs, potentially wreaking havoc on pharmaceutical firms profits, which depend on the blockbusters to fund research. As David Balto, a former FTC official said, "Branded pharmaceutical firms have been stretching the limits of what deserves a patent, and the courts are just catching up."