Antibody Claims Must Move Toward Structure, Panelists Say

Life Sciences Law & Industry Report connects the dots among the many disciplines that make up the burgeoning life sciences industry, with biweekly updates on current regulatory, legislative,...

By John T. Aquino

Nov. 17 — Applicants for antibody patents in the U.S. are finding it difficult to secure broad functional claims for antibodies and should be claiming structure, panelists at a biotech intellectual property conference said Nov. 17.

And in Europe, it is difficult to secure specific antibody product claims, they said.

“There's a misalignment between the two systems that applicants have to confront,” said Fangli Chen of Choate Hall & Stewart LLP. “And this is against a backdrop of a number of challenges to antibody patent claims that are brewing—currently over 200.”

Matthew A. Pearson of Akin Gump Strauss Hauer & Feld LLP said that several recent court decisions, influenced by advances in science, have caused a rethinking of how to draft antibody-related claims.

Making an antibody claim can be so complicated that Ken Dow, vice president of patents and assistant patent counsel for Johnson & Johnson, showed the session audience an “antibody claim decision tree,” with a series of steps guided by whether the answers are yes or no—“Is there a novel target? If no, are the antibodies known? If yes, are the human antibodies known? If no, then you need to have affinity and biological activity data.”

Chen moderated the session “Antibody Drug Protection—a Tale of Two Systems” at the BIO Intellectual Property Counsels Committee meeting in Cary, N.C.

Big, Lifesaving Business

Antibodies are a class of proteins that are produced by plasma cells used by the immune system to protect the body against pathogens. They attach to an antigen—a “hook” in the cell's surface that is partially responsible for what goes in and out of the body—to sterilize or kill the harmful substance. Antibodies have been called “magic bullets,” Chen said.

She described the importance of antibodies, which she characterized as both “big business” and as “diagnostic agents and therapeutic agents for the treatment of such diseases as breast cancer, leukemia, arthritis and Crohn's disease and transplant rejection.” Chen said, “With its $160 billion in sales,” antibodies make up “approximately 50 percent of the global biotech drug market.”

She noted that:

• at least 34 monoclonal antibodies were approved either in the U.S. or Europe as of March 2012;
• six novel therapeutic antibodies were approved in 2014, two have already been approved in 2015 and six are under regulatory review in Europe and the U.S.; and
• current investment in the clinical and diagnostic development of monoclonal antibodies is “enormous.”

 

Moving to Claim Structure, Not Function

But recent decisions by the U.S. Court of Appeals for the Federal Circuit have shaken up the world of antibody patents, Pearson said.

Most recently, in AbbVie Deutschland GmbH & Co. v. Janssen Biotech, Inc., 2014 BL 183329, 759 F.3d 1285, 111 U.S.P.Q.2d 1780 (Fed. Cir. 2014) (8 LSLR 650, 7/11/14), the Federal Circuit affirmed a jury finding of invalidity of AbbVie's claims directed to fully human antibodies that bind to and neutralize the activity of human interleukin 12 (IL-12), overproduction of which can cause psoriasis and rheumatoid arthritis, for lack of adequate written description under 35 U.S.C. § 112. The court's ruling called into question what has been a usual practice of making antibody claims—claiming a group, or genus, of related antibodies on the basis of an antigen with only particular antibodies disclosed and distinguished by function.

The court focused on the requirement that a sufficient description of a genus requires either a “representative number of species” or “structural features common to the members of the genus” and concluded that AbbVie didn't show the structural features common to the genus, Pearson said.

Dow said, “In the 1990s, it made sense for applicants to be able to utilize what the U.S. Patent [and Trademark] Office called the ‘antibody exception,' which suggested that disclosure of an antigen alone can provide written description support for any antibody that binds to that antigen. But with advances of science, such a broad claim no longer seems appropriate.”

At the BIO 2015 International Convention in Philadelphia in June (9 LSLR 754, 6/26/15), Robin Silva of Morgan Lewis said, “Companies are no longer filing AbbVie-like claims and are reading the AbbVie decision to find different scenarios to be able to claim function” to secure antibody patents. She advised, “If you can claim structure, claim structure and not function. That's the best way.”

Antibodies as Viewed by EPO

Hugh Goodfellow of the London-based law firm Carpmaels & Ransford described different types of antibody claims and how they fare in the European patent system.

A claim that covers an antibody “that binds antigen X” is commonly used when the antigen itself isn't well-known, Goodfellow said. “These are very broad claims, but the EPO [European Patent Office] has been very generous with these, even notoriously so in Human Genome Sciences, Inc. v. Eli Lilly and Co., U.K.S.C., No. 51, 11/2/11, in which the U.K. Supreme Court overturned an appeals court's ruling and held that Human Genome Sciences had provided enough clarity to show that the product in dispute could plausibly be used for research work.”

For a claim such as “neutralizing antibody that binds [antigen] X within an affinity of Y,” affinity is the measure of the strength of interaction between the part of the antigen known as the epitope and an antibody's antigen binding site. Goodfellow said, “These claims, which focus on functional properties, are valuable ones to block other innovators, but they bring up issues of clarity—how do you measure the functionality?—and of the inventive step—what is so special about your antibody? The inventive step might come from the method developed to make the antibody or from the surprising advantages of the class of antibodies,” Goodfellow said.

Discussing claims that read, “Antibody against X +sequences properties,” Goodfellow said that his type of claim focuses on structural properties of the antibodies and can be useful in anticipating the development of biosimilar antibodies.

“The EPO doesn't recognize structural non-obviousness like the U.S. Patent and Trademark Office does,” he said. “What the EPO wants is to see unexpected properties, a surprising technological effect based on high affinity.”

To contact the reporter on this story: John T. Aquino in Washington at jaquino@bna.com

To contact the editor responsible for this story: Nancy Simmons at nsimmons@bna.com