A long-running cholesterol drug dispute between Amgen and Sanofi in 2020 will return to the same federal court that killed off one test for determining how antibodies can be patented.
The case is important for drugmakers and biotechnology companies because it comes in the wake of the U.S. Court of Appeals for the Federal Circuit’s 2017 decision narrowing the patents companies can claim for the antibodies they discover. That called into question many existing biotech patents. Patent attorneys are closely watching the Amgen and Sanofi dispute to see if the court adds new restrictions.
“The decision does have the potential to significantly limit the scope of claims to antibodies,” said Kevin Noonan, a Chicago-based patent attorney and partner with McDonnell Boehnen Hulbert & Berghoff LLP.
The case centers on patents for market leader Amgen Inc.’s cholesterol drug Repatha, which a federal judge in the U.S. District Court for the District of Delaware invalidated in August. That cleared the way for Sanofi and Regeneron Pharmaceuticals Inc. to continue selling their competing Praluent.
The two Amgen patents, which were due to expire in August 2028, are related to antibodies called PCSK9 inhibitors, which help patients with ultra-high bad—or LDL—cholesterol who can’t get their condition under control with widely used statins such as Pfizer’s Lipitor.
Prior Test Struck Down
Having been sent back to the Delaware District Court after the U.S. Supreme Court passed, the case returns to the Federal Circuit on appeal once again in the wake of the appeals court’s 2017 decision limiting how antibodies can be patented. Previously, companies relied on the “newly characterized antigen test,” which allowed patent owners to claim an entire genus of antibodies using only a description of the structure of a corresponding antigen.
Antigens are foreign substances, including components of disease organisms or even cancer cells, that evoke immune responses in the body. Antibodies are blood proteins that are produced in response to a specific antigen. A genus can contain many variations of antibodies that respond to the specified antigen, but which may be found to respond to other antigens as well.
In other words: By describing the antibody response, patent holders could previously obtain exclusivity on the antibody’s response to a broad array of corresponding antigens.
“The reason that’s important is a lot of times in the biotech industry they come up with an antibody and they may not appreciate all the ways it has effects,” Aziz Burgy, a patent attorney and partner with Axinn’s Washington, D.C., office, said. “When they first discover it, they may think that it has applications for diseases A, B, and C, but as they do more research they may find it has more applications for diseases D through G.”
The Federal Circuit put an end to the test by ruling that it failed to satisfy Section 112 of the Patent Act—specifically, the written description requirement. The provision mandates that a patent’s specification must describe the claimed invention in sufficient detail to the point that someone skilled in the field could reasonably conclude that the inventor legitimately owned the invention being claimed in the patent.
The U.S. Patent and Trademark Office followed up in February 2018 with a memo that officially withdrew the test to be consistent with the Federal Circuit’s ruling.
Watching Existing Patents
The decision raised questions about the validity of many existing biotech patents, and many lawyers in the field say they’re watching to see what happens in this case next year because the stakes are high.
“You could see a lot more patents where, for example, instead of just having one patent claiming a vast array of different antibodies, you could probably see either varied claim scope or more applications being submitted covering more narrow aspects as the research goes on with respect to those antibodies,” Burgy said.
“I think you could see rather than companies trying to file one really broad patent, they may just do it in such a way that they’re serially getting patents on different aspects of the different antibodies,” he added.
The case is Amgen, Inc. v Sanofi, Fed. Cir., No. 20-01074, filed 10/24/19.