The PTO recently released reexamination stats through 3Q of the fiscal year (ending June 2007). Both ex parte and inter partes filings are heading towards record totals. 477 ex parte reexam requests have been filed year-to-date, compared to 340 last year; a 40% jump. Inter partes reexam outings more than doubled: 90 versus 40. 70 requests were filed for all of fiscal 2006.

Inter partes reexamination introduces litigation estoppel under 35 U.S.C. 315(c): a third-party requester cannot reassert invalidity in litigation against a patent that survives; the patent is untouchable.

35 U.S.C. § 315 (c) Civil Action.- A third-party requester whose request for an inter partes reexamination results in an order under section 313 is estopped from asserting at a later time, in any civil action arising in whole or in part under section 1338 of title 28, the invalidity of any claim finally determined to be valid and patentable on any ground which the third-party requester raised or could have raised during the inter partes reexamination proceedings. This subsection does not prevent the assertion of invalidity based on newly discovered prior art unavailable to the third-party requester and the Patent and Trademark Office at the time of the inter partes reexamination proceedings.

Litigation estoppel applies to as far as any ground that could have been raised. That includes any prior art that should have been discovered. But the upward trend indicates that previous worries have been assuaged by the anti-patent fervor that seems to have gripped the nation.

Currently, half of the pending inter partes reexams are co-pending with litigation, up from a comparable 26% last year.

Almost all (92%) ex parte reexamination requests are granted. Once granted, odds are on for amended claims: 64%. All claims are confirmed in 26% of ex parte reexams, with all claims canceled only 10% of the time. In other words, claims are canceled or amended in almost 75% of ex parte reexaminations.

The stats run higher for hell breaking loose with inter partes reexams: 96% of requests are granted. Only eight inter partes reexaminations have been completed, but all the claims have been axed in seven of eight.