IP Law Bulletin

May 17, 2011

Centocor Ortho Biotech, Inc. (Centocor) filed a patent infringement suit in the Eastern District of Texas alleging that Abbott's Humira® antibody infringed claims of its U.S. Patent No. 7,070,775 (the '775 patent). After a $1.67 billion jury verdict finding Abbott liable for willful infringement, Abbott moved for judgment as a matter of law (JMOL) on invalidity, noninfringement, damages, and willfulness. The district court only granted the motion for JMOL on willfulness, denying the others, and Abbott appealed. In Centocor Ortho Biotech, Inc. v. Abbott Laboratories, the Federal Circuit reversed and held that the asserted claims were invalid for lack of written description.

The technology at issue in this case involved antibodies to human TNF-α, overproduction of which can lead to several autoimmune diseases. Centocor and Abbott both developed antibodies to neutralize human TNF-α using different approaches. Centocor started with a mouse antibody that had high affinity and high neutralizing activity, and then modified it to make it look more human to reduce the problem of immunogenicity. Centocor filed a patent application disclosing its A2 mice antibodies and chimeric antibodies, with mouse variable regions and human constant regions, in 1991. Centocor subsequently filed several continuation-in-part (CIP) applications. The asserted claims of the '775 patent, directed to human variable regions, were first filed in 2002 and claimed priority to an application filed in 1994.

Abbott pursued an alternative path, engineering a fully human antibody that did not have immunogenicity problems, and worked to improve the binding affinity and the neutralizing activity. Abbott filed a patent application disclosing their fully human antibody in 1996. The patent issued in 2000 as U.S. Patent 6,090,382, and Abbott obtained regulatory approval to market Humira® in 2002. Centocor's claims to fully human antibodies were not filed until after this time, and ultimately issued in 2006 as the ‘775 patent.

The Court stated that the pivotal issue in the case was whether the ‘775 patent provided adequate written description for the claimed human variable regions using the test as confirmed in Ariad. As noted above, the asserted claims of the ‘775 patent directed to human variable regions were not filed until 2002, after Abbott had already patented a fully-human antibody to TNA-α. Since Abbott’s claims were filed in 1996, Centocor relied on the priority claim to the 1994 CIP application, which meant the asserted claims of the ‘775 patent needed to find written description support in the 1994 CIP application. 

The specification of the 1994 CIP application did not disclose a fully human antibody or a single human variable region. The court found that a few sprinkled references to human antibodies or human variable regions did not reasonably suggest that Centocor was in possession of these antibodies. Nor was the fact that a fully human antibody could be made sufficient to show that the inventors of the ‘775 patent possessed such an antibody. At best, the specification described a plan, when what was required is constructive possession. The written description requirement does not demand either examples or an actual reduction to practice, but it does demand that one of skill in the art can “visualize or recognize” the claimed antibodies based on the specification’s disclosure.

One of Centocor’s arguments was that an earlier Federal Circuit decision, Noelle v. Lederman, 355 F.3d 1343 (Fed. Cir. 2004), and the United States Patent and Trademark Office’s written description guidelines support the view that disclosing a protein, in this case human TNF-α, provides adequate written description for any antibody that binds to that protein. The Court clarified that this reasoning only applies to disclosure of newly characterized antigens where creation of the claimed antibodies is routine. Here, both the human TNF-α protein and antibodies to it were already known. The claimed invention in the instant case is a class of antibodies containing a human variable region that have the particularly desirable therapeutic properties of high affinity, neutralizing activity, and A2 specificity. Claiming antibodies with specific properties can result in a claim that does not have written description support, even if the human TNF-α protein is disclosed, since antibodies with those properties have not been adequately described. 

The Court overturned the jury award, finding that there was inadequate written description for the fully human antibody and noting that Centocor could not “overreach the scope of [its] contribution to the field of art as described in the patent specification.” While this case does not represent any significant departure from existing written description law, it does underscore a predicament in the “unpredictable” arts:  while narrow claims tend to limit the value of patent protection, broad claims may be susceptible to invalidity attack on written description grounds. Some commentators view this decision as indicative of a trend at the Federal Circuit to use the written description requirement to prevent overreaching by holders of broad, pioneering biotech patents, a trend which may soon expand into the more “predictable” arts.

This advisory was prepared by Nutter's Intellectual Property practice. For more information, please contact your Nutter attorney at 617-439-2000.

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