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March 8, 2009


The validity of a granted patent may be challenged before the USPTO at any time during a patent's life. There are two types of reexamination: ex parte and inter partes. Both start by petition to the Office, with the petitioner citing "a substantial new question" of patentability in the form of prior art. The older ex parte form comprises a one-shot injection of prior art. Inter partes reexamination, introduced in 1999, affords the petitioner continued kibitzing. At a cost.

Ex parte reexaminations came into being in 1981. Ex parte reexams may be initiated by a patent owner or by a third party, and a third party may petition anonymously. Ex parte reexam is covered in MPEP 2200.

Inter partes reexaminations (MPEP 2600) are the hardcore form of reexamination. MPEP 2601 -

The optional inter partes alternative provides third party requesters with a greater opportunity to participate in reexamination proceedings, while maintaining most of the features which make reexamination a desirable alternative to litigation in the Federal Courts (e.g., low cost relative to Court proceedings, expedited procedure).

They're just kidding about inter partes reexam being "expedited." As Professor Crouch noted: "The first request for inter partes reexamination was made in 2001 and still no contested inter partes reexamination has completed its course."

Inter partes reexamination is permitted only for patents filed on or after November 29, 1999.

Reexamination has repeatedly been used as a strategic tool for a patent litigation defendant. One stratagem has been to use it as a last resort - upon losing in court, file reexamination to limit the damage.

For a defendant in serious denial, and not wishing to put the matter in the past anytime soon, there is the "gum-the-works" stratagem of filing a reexam, and then petitioning the court for a stay. Courts have been repeatedly suckered by the "expedited procedure" mirage, and have granted stay of litigation pending reexam. Getting a stay typically only works early on, before discovery. Once the litigation train leaves the station and the process gets underway, getting a stay granted becomes increasingly problematic for a defendant.

Inter partes reexamination allows a third party to drive the process all the way to the CAFC if patent damnation is not forthcoming from the PTO.

Flagging down the attention of the patent office over errant examination does not come cheap. An ex parte petition presently costs $2,520. Those wishing to dabble inter partes will first part with $8,800.

Inter partes reexam has been slow to catch on, particularly compared to ex parte, but has gained traction in recent years. The reason for that is that more patents are being litigated of a vintage, i.e., post-1999, for which inter partes applies.

Year Inter Partes
2001 2
2002 6
2003 24
2004 37
2005 48
2006 91
2007 123

Lawyers hate ceding a hand on the rudder, hence the preference for inter partes.

Each time the patent owner responds to an Office action, the third party requester may comment on the Office action and the patent owner response, and thereby participate in the proceeding. - MPEP 2654, citing 35 U.S.C. § 314.

There is a cheap seat into the action, a no-cost approach to notifying the world of potentially invalidating prior art. 35 U.S.C. § 301 -

Any person at any time may cite to the Office in writing prior art consisting of patents or printed publications which that person believes to have a bearing on the patentability of any claim of a particular patent. If the person explains in writing the pertinency and manner of applying such prior art to at least one claim of the patent, the citation of such prior art and the explanation thereof will become a part of the official file of the patent. At the written request of the person citing the prior art, his or her identity will be excluded from the patent file and kept confidential.

For unsurpassed quality at an economical cost, Patent Hawk invalidates patents and prepares excellent reexamination petitions.

Matthew A. Smith of Foley & Lardner has written an excellent treatise on Inter Partes Reexamination.

A hat-tip of thanks to Professor Crouch at Patently-O.

Posted by Patent Hawk at March 8, 2009 10:47 PM | Prosecution


Hawk, any idea how many post-issue oppositions at the 30 year old EPO (which are full-blown disputed inter partes proceedings) have by now run their full course to final unappealable Decision? Any idea what the average number of months is, between giving notice of opposition and that final Decision (that will wipe the patent out for the whole of 570 million inhabitant Europe)? My guess: 100,000 Decisions and 48 months. No wonder the 2009 Bill proposes post-issue opposition. AND, may I ask, have you experience of the European equivalent of 35USC301, namely Art.115, EPC?

Posted by: MaxDrei at March 10, 2009 12:43 AM

PS. I must say that I did smile at your choice of accompanying image. Nice one. Brightened up my day no end.

Posted by: MaxDrei at March 10, 2009 12:44 AM