Tuesday, July 22, 2008

Appeal of Dr. Reddy's, Teva rejected in rabeprazole case

The CAFC affirmed the decision of SDNY in Eisai v. Dr. Reddy's and Teva, sending appellants Dr. Reddy's (represented by Budd Larner) and Teva (represented by Goodwin Procter) to the showers.

The drug concerned was rabeprazole, which is part of a class of drugs known as proton pump inhibitors, which suppress gastric acid production by inhibiting action of the enzyme H+K+ATPase. The patent was 5,045,552.

Teva argued before the district court and maintains on appeal that the ’552 patent is invalid for obviousness. Dr. Reddy's argued inequitable conduct, but not obviousness.

In re Dillon was cited, as was KSR:

Where, as here, the patent at issue claims a chemical compound, the analysis of
the third Graham factor (the differences between the claimed invention and the prior art)
often turns on the structural similarities and differences between the claimed compound
and the prior art compounds. See Eli Lilly & Co. v. Zenith Goldline Pharms., Inc., 471
F.3d 1369, 1377 (Fed. Cir. 2006) (noting that, for a chemical compound, a prima facie
case of obviousness requires “structural similarity between claimed and prior art subject
matter . . . where the prior art gives reason or motivation to make the claimed
compositions” (quoting In re Dillon, 919 F.2d 688, 692 (Fed. Cir. 1990) (en banc))).
Obviousness based on structural similarity thus can be proved by identification of some
motivation that would have led one of ordinary skill in the art to select and then modify a
known compound (i.e. a lead compound) in a particular way to achieve the claimed
compound. See Takeda Chem. Indus. v. Alphapharm Pty., Ltd., 492 F.3d 1350, 1356
(Fed. Cir. 2007). In keeping with the flexible nature of the obviousness inquiry, KSR
Int’l Co. v. Teleflex Inc., 127 S. Ct. 1727, 1739 (2007), the requisite motivation can
come from any number of sources and need not necessarily be explicit in the art. See
Aventis Pharma Deutschland GmbH v. Lupin, Ltd., 499 F.3d 1293, 1301 (Fed. Cir.
2007). Rather “it is sufficient to show that the claimed and prior art compounds possess
a ‘sufficiently close relationship . . . to create an expectation,’ in light of the totality of the
prior art, that the new compound will have ‘similar properties’ to the old.” Id. (quoting
Dillon, 919 F.2d at 692).

Teva seemed to have trouble with its expert: The trial court specifically noted that Teva’s expert testified with respect to
the EP ’726 data that “[t]he level of acid secretion . . . from these [anti-ulcer] data . . .
cannot be determined.” (...) And Teva’s expert identified
a separate reference teaching that fluorine-substituted groups increase lipophilicity. Id.
The record, however, shows no discernible reason for a skilled artisan to begin with
lansoprazole only to drop the very feature, the fluorinated substituent, that gave this
advantageous property. Indeed, Teva’s pharmacology expert, Dr. John Forte, declined
to opine on lansoprazole’s relevance to an examiner assessing the patentability of
rabeprazole. J. A. at 14894. And Dr. Reddy’s pharmacology expert, Dr. Simmy Bank,
testified in deposition that “I thought [lansoprazole] had nothing to do with this trial.”

The CAFC seemed to think that Teva had a bad theory on obviousness, post-KSR:

In other words, post-KSR, a prima facie case of obviousness for a chemical
compound still, in general, begins with the reasoned identification of a lead compound.
Teva cannot create a genuine issue of material fact on obviousness through the
unsupported assertion that compounds other than lansoprazole might have served as
lead compounds. Further, the record contains no reasons a skilled artisan would have
considered modification of lansoprazole by removing the lipophilicity-conferring
fluorinated substituent as an identifiable, predictable solution. In sum, the district court
properly concluded that the record did not support a case of obviousness of the ’552
patent as a matter of law.

Of inequitable conduct:

Inequitable conduct in prosecuting a patent application before the United States
Patent & Trademark Office may take the form of an affirmative misrepresentation of
material fact, a failure to disclose material information, or the submission of false
material information, but in every case this false or misleading material communication
or failure to communicate must be coupled with an intent to deceive. Innogenetics, 512
F.3d at 1378 (citations omitted).

The CAFC rejected various contentions

failure to disclose a co-pending application
failure to disclose prior art
false and misleading affidavit
failure to disclose prior application for lansoprazole [The strongest evidence of some problem
was the passing comment of one Eisai “insider” that the similarity of lansoprazole and
rabeprazole “bothers me.”


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