Purdue v. Endo: the changing faces of inequitable conduct

Christopher Cotropia wrote about the 2005 case Purdue v. Endo in the Jan. 2006 issue of JPTOS (88 JPTOS 46). Unfortunately on February 1, 2006, that decision was vacated and replaced by 2006 U.S. App. LEXIS 2887.

From the Cotropia article:

Purdue Pharma L.P. v. Endo Pharmaceuticals
Inc., 410 F.3d 690 (Fed. Cir. 2005)

A unanimous Federal Circuit panel in Purdue Pharma L.P. v. Endo
Pharmaceuticals, Inc. found statements made by an applicant to be material for purposes
of inequitable conduct when the statements (a) where used to distinguish
his invention over the prior art and (b) implied experimental results that
had been obtained when actually such statements were based on only the
inventor's insight.

(...)

Purdue is a significant case because, due to the early
nature of patent disclosures, inventors rarely have scientifically, fully
established every aspect of their invention. So statements such as those that
appear in the written description in Purdue are not uncommon. These statements alone,
however, are not what the court focuses on to find materiality. It is the
reliance on these statements to overcome a rejection. Therefore, Purdue is a
reminder to the patent prosecutor to communicate with the inventor or inventors
throughout the prosecution process and make sure, when relying on something such as
unexpected results, that there truly are results upon which to base that argument.