Pfizer Earns One More Victory in Norvasc Litigation

    By Robert Dailey —

This week Pfizer won another courtroom battle against
generic drug manufacturer Synthon in the companies' ongoing dispute over
Pfizer's drug Norvasc.  The District
Court held two Synthon patents, U.S. Patent Nos. 6,653,481 and 6,858,738
unenforceable due to inequitable conduct.  Pfizer had already prevailed over Synthon in a jury trial that addressed
noninfringement and invalidity.

The Synthon patents disclose methods and intermediates
useful for synthesizing Norvasc.  Pfizer,
however, has been using these methods and intermediates since the late 1980s,
and disclosed them in printed publications in 1989 and 1996.  Synthon's earliest alleged invention occurred
in late 1999.  But since the facts
demonstrated that Synthon scientists had based their work off of Pfizer
publications, the Court concluded that Synthon scientists committed
inequitable conduct.

Despite the difficulty of proving inequitable conduct,
Synthon's actions left little doubt in this instance.  First, the project supervisor possessed a
binder labeled "Maps" whose first page was a Pfizer document
describing the method and intermediates that Synthon would later claim in its
patents.  Second, the supervisor had
faxed a copy of the Pfizer document to one of the named inventors.  Third, the literature file for the Norvasc
project contained a copy of this same Pfizer document.  Yet Synthon never disclosed this Pfizer
document to the Patent Office during the prosecution of either patent.

Synthon had also prepared two internal monographs that
referred directly to the Pfizer document and described Pfizer's synthetic
pathway.  Both monographs were prepared
before Synthon's alleged date of conception, and one even listed one of the
inventors as its author.  Meanwhile,
another inventor had saved a document on his computer entitled "route
according to Pfizer."

Yet throughout the prosecution of its patents, Synthon
referred to its claimed intermediate as a "new" compound.  Synthon even submitted a Rule 131 affidavit
by one of the "inventors" to swear behind the dates of two pieces of
prior art.  Furthermore, Synthon
mischaracterized the nature of the Pfizer method when the Examiner asserted
Pfizer composition patent as prior art.

It seems that the scientists and project managers kept
Synthon's in-house patent counsel in the dark on the whole matter.  And at trial, these scientists and managers
could not recall having any knowledge of the Pfizer method.

To prove inequitable conduct, the defendant must prove
that the plaintiff withheld material documents or information from the PTO and
did so with deceptive intent.  First, the
District Court held that the withheld Pfizer publication and Synthon's false
statements to the PTO were material.  The
withheld document would have anticipated claims in both patents, and the false
statements were used to overcome prior art.  Next, the Court held that the facts demonstrated that the Synthon
inventors had intended to deceive the PTO.  The Court acknowledged that a defendant cannot prove deceptive intent
simply by showing an absence of good faith on the part of the inventors.  Yet a plaintiff cannot avoid inequitable
conduct simply by asserting forgetfulness in the face of facts that tend to
show bad faith.

Pfizer officials have announced that they will week
attorney's fees against Synthon for its conduct in this litigation.

In a related case, Pfizer recently defeated Synthon's
efforts to launch a generic version of Norvasc.  See Pfizer, Inc. v. Synthon Holdings BV, No. 1:05CV39 (M.D.N.C. 2006).

Synthon IP, Inc. v. Pfizer Inc., No. 1:05cv1267 (E.D. Va. 2007).

Additional information regarding this case can be found at the Orange Book Blog.

Robert Dailey, Ph.D., is a physical chemist and a third-year law
student at the University of North Carolina at Chapel Hill.  Dr. Dailey
was a member of MBHB's 2006 class of summer associates.