...is the tactic described in a Times article over the weekend:
[The] Coalition for Affordable Drugs . . . identif[ies] pharmaceutical patents that they consider weak or abusive. Then they request that a unit of the United States Patent and Trademark Office review the legitimacy of the patents. . . . [Founders] Mr. Bass and Mr. Spangenberg say the coalition’s aim is to bring down drug prices that are kept artificially high by dubious patents.
The Times reports that the Coalition has an impressive 50% success rate in their challenges so far. The article also describes some of the ways industry tries to game the system to keep prices high, including patenting nearly-identical drugs when the original patent is about to expire (which extends the life of the patent), and paying generic competitors to stay off the market ("pay for delay").
Read more here.