Supreme Court Rules for Sanofi in Patent Dispute with Amgen

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The US Supreme Court has voted unanimously to affirm a previous Federal Circuit ruling that invalidated Amgen’s two cholesterol drug patents.

The patents are for antibodies engineered to help reduce levels of low-density lipoprotein (LDL) cholesterol, sometimes called “bad” cholesterol because it can lead to cardiovascular disease, heart attacks, and strokes.

As the Court noted,

The immune system produces antibodies as a defense to foreign agents called antigens. When a particular antigen—a virus, for example—enters the body, the immune system generates antibodies to attack it. In a successful attack, the antibodies target and bind to the antigen, stopping it from causing harm to the body.

To treat patients with high LDL cholesterol, scientists investigated how antibodies could be used to inhibit PCSK9 -- a protein that binds to and degrades LDL receptors responsible for extracting LDL cholesterol from the bloodstream.

Amgen and Sanofi each developed a PCSK9-inhibiting drug. In 2011, Amgen obtained a patent for the antibody employed in its drug, and Sanofi received one for the antibody used in its own drug.

Amgen’s drug was marketed under the name Repatha, and Sanofi’s was called Praluent. Each drug uses a different antibody with its own unique amino acid sequence.

The dispute before the Supreme Court concerned two more patents Amgen obtained in 2014 that relate back to the company’s 2011 patent. These later patents purport to claim for Amgen “the entire genus” of antibodies that (1) “bind to specific amino acid residues on PCSK9,” and (2) “block PCSK9 from binding to [LDL receptors].”

Amgen identified the amino acid sequences of 26 antibodies that perform these two functions, and its submission to the Patent Office depicted the three-dimensional structures of two of these 26 antibodies.

Amgen also offered two methods to make other antibodies that perform the binding and blocking functions.

One, called the “roadmap,”

directs scientists to: (1) generate a range of antibodies in the lab; (2) test those antibodies to determine whether any bind to PCSK9; (3) test those antibodies that bind to PCSK9 to determine whether any bind to the sweet spot as described in the claims; and (4) test those antibodies that bind to the sweet spot as described in the claims to determine whether any block PCSK9 from binding to LDL receptors.

Another method, called “conservative substitution,” requires scientists to:

(1) start with an antibody known to perform the described functions; (2) replace select amino acids in the antibody with other amino acids known to have similar properties; and (3) test the resulting antibody to see if it also performs the described functions.

Amgen sued Sanofi for infringing its 2014 patents. Sanofi contended that it wasn’t liable for patent infringement because Amgen’s relevant claims were invalid under the Patent Act’s “enablement” requirement.

The enable requirement of 35 U. S. C. §112(a) requires a patent applicant to describe the invention “in such full, clear, concise, and exact terms as to enable any person skilled in the art . . . to make and use the [invention].”

Sanofi claimed that Amgen’s methods for generating additional antibodies were little more than trial-and-error. Sanofi also argued that that Amgen was trying to claim the exclusive use of potentially millions more antibodies than its patents had taught persons skilled in the art to make.

The district court and Federal Circuit agreed with Sanofi.

The Supreme Court noted that

The patent “bargain” describes the exchange that takes place when an inventor receives a limited term of “protection from competitive exploitation” in exchange for bringing “new designs and technologies into the public domain through disclosure” for the benefit of all. … From the Patent Act’s beginnings, Congress has sought to ensure the benefit of this bargain for the public by requiring the patent applicant to deposit a “specification . . . so particular . . . as not only to distinguish the invention or discovery from other things before known and used, but also to enable a workman or other person skilled in the art or manufacture . . . to make, construct, or use the same.”


If a patent claims an entire class of processes, machines, manufactures, or compositions of matter, the patent’s specification must enable a person skilled in the art to make and use the entire class.

For example, in O’Reilly v. Morse (involving the inventor of Morse Code), the Court held that one of the claims in Morse’s patent for a telegraphic system was “too broad, and not warranted by law” because it covered ALL means of telegraphic communication but didn’t describe how to make or use them all.

Similarly, in the Incandescent Lamp case, the inventors of an “electric lamp” with an “incandescing conductor” made of “carbonized paper” claimed that a lamp created by Thomas Edison infringed their patent because it used bamboo as a conductor. The Court sided with Edison because the rival inventors made an over- broad claim for “every fibrous and textile material.”

In this case, found the Court, Amgen’s patent claims were broader than the 26 exemplary antibodies it identified by their amino acid sequences:

While Amgen seeks to monopolize an entire class of things defined by their function—every antibody that both binds to particular areas of the sweet spot of PCSK9 and blocks PCSK9 from binding to LDL receptors—the record reflects that this class of antibodies does not include just the 26 that Amgen has described by their amino acid sequences, but a vast number of additional antibodies that it has not.

The Court agreed with Sanofi that the “roadmap” and “conservative substitution” approaches were “little more than two research assignments.”

The “roadmap,” said the Court, “merely describes step-by-step Amgen’s own trial-and-error method for finding functional antibodies,” and “conservative substitution” was not much different.

The Court concluded:

Section 112 of the Patent Act reflects Congress’s judgment that if an inventor claims a lot, but enables only a little, the public does not receive its benefit of the bargain. For more than 150 years, this Court has enforced the statutory enablement requirement according to its terms. If the Court had not done so in Incandescent Lamp, it might have been writing decisions like Holland Furniture in the dark. Today’s case may involve a new technology, but the legal principle is the same.

Categories: Patents