Christopher Newman Editor

“This is a showdown about whether the most valuable patents in the entirety of the patent system are valid,” one law expert said.

The nearly decade-long patent feud between Amgen and rivals Sanofi and Regeneron has divided the biopharmaceutical industry, with drugmakers taking different sides in a U.S. Supreme Court case that could have far-reaching effects. 

At issue are patents for powerful cholesterol-lowering medicines known as PCSK9 inhibitors. Regeneron and Sanofi brought the first, Praluent, to market in 2015. Amgen followed one month later with a similar medicine, called Repatha. The drugs work by boosting liver cells’ ability to hoover up LDL, or “bad,” cholesterol.  

Amgen has long claimed Sanofi and Regeneron infringed on patents it secured for Praluent. The fight has slowly winded its way through the U.S. legal system to reach the Supreme Court. There, judges could disrupt the $160 billion-per-year market for antibodies by deciding how broadly patent claims can be drawn around the targets of drugs like PCSK9 blockers.

“This is a showdown about whether the most valuable patents in the entirety of the patent system are valid,” said Jacob Sherkow, a University of Illinois professor who specializes in bioscience law and co-authored a brief on the case. 

Amgen argues it can use “genus claims” to protect Repatha, a broad type of patent claim that would allow it to block other antibody drugs that similarly bind to PCSK9. It’s joined by AbbVie, GSK, Biogen, Bristol Myers Squibb and others, many of whom say such claims are critical to support innovation. They may also stand to benefit with antibody medicines of their own for other diseases. 

“When a pioneering inventor files a patent application disclosing to the world a breakthrough invention with broad applicability, the inventor deserves a correspondingly broad scope of patent protection,” wrote lawyers for AbbVie.

Sanofi and Regeneron counter that Amgen’s claim goes beyond what it actually has invented — akin to claiming “all things that fly” between certain altitudes but only listing a few examples, as one group of scientists wrote in a court brief. In their and the companies’ view, such a broad grant of patent protection would stall development of other and possibly better drugs aimed at the same target.

They have a lengthier list of drugmaker allies — including Pfizer, Bayer, AstraZeneca, Roche’s Genentech division and Johnson & Johnson. “This was no pioneering invention. PCSK9 was known, its effect on LDL levels and its binding to the LDL receptor were known,” wrote lawyers for Pfizer, which like Regeneron had researched anti-PCSK9 antibodies before Amgen first disclosed specific antibodies in a 2009 patent application. 

Patents as broad as Amgen seeks are “going to mean less treatment options for patients, and at the end of the day, that’s probably not a good thing,” said Sean Tu, a law professor at West Virginia University in Morgantown who co-authored a brief in support of Sanofi, in an interview. 

Multiple drugs are often developed against the same target, leading to at times intense competition between drugmakers. Tu cited a brief that gave, as examples, 10 groups of widely used medicines sharing the same target to treat cancers, high cholesterol, HIV and immune diseases.

A central question in the case is whether Amgen’s patents meet a legal standard known as enablement, which requires the invention be described well enough to allow a skilled person in the field to use it. Amgen claims all antibodies that bind to a “sweet spot” on PCSK9 and thereby inhibit its action.

Two juries have found Amgen’s claims valid, but each time the case was appealed to the main federal court for patent cases, the U.S. Court of Appeals for the Federal Circuit. Both times that court ruled against Amgen’s broad claims. 

Emily Johnson, head of intellectual property policy and advocacy at Amgen, has claimed the federal circuit applied a heightened standard for enablement that goes beyond what was required in the past. The antibodies described in Amgen’s patents are produced by a screening process that is automated, low cost and has been around for decades, she said.

“We went through two jury trials, and the defendants had the opportunity to come forward with evidence to show that there was some type of antibody that couldn’t be made using the patent’s teachings, and ultimately, the jury found in Amgen’s favor both times,” she said.

Lawyers for Sanofi and Regeneron have countered that there are millions of potential candidate antibodies — so many that a scientist could spend 100 years immunizing mice and still not create a particular antibody. “Amgen has claimed far more than it has enabled,” they wrote.

Much of the challenge in patenting antibodies stems from advances that have allowed scientists to better understand their structure and the proteins they target, Sherkow and another law professor, Mark Lemley, argued in a February article in the Yale Law Journal. This has allowed patent claims to shift toward written descriptions and away from simpler explanations of antibodies’ function. 

Claiming antibodies via their function could impede discovery of other drugs acting via the same target that might be more effective. But requiring a specific written description of every antibody permutation isn’t feasible either, Sherkow and Lemley note. This has left drugmakers like Amgen, Sanofi and Regeneron litigating over where the lines should be drawn.

Reference: www.biopharmadive.com