Has The Federal Circuit Just Put The Final Nail In The Coffin Of Broad Functional Genus Claims?

• Published date: 19 August 2021
• Subject Matter: Intellectual Property, Food, Drugs, Healthcare, Life Sciences, Patent, Food and Drugs Law
• Law Firm: Haug Partners
• Author: Mr Brian V. Slater and Audrey Sparschu

In a development having significant ramifications for many biopharma companies, the Federal Circuit has denied Amgen's petition for rehearing en banc a decision invalidating a genus patent covering its antibody cholesterol treatment, Repatha'. Amgen's petition, joined by several amici, argued that the Federal Circuit's heightened enablement standard under section 112 of the Patent Act improperly invalidates virtually all genus claims having functional limitations, and that enablement should be a question of fact, not law.¹ In a non-precedential per curiam order issued last week, the court declined to rehear the case without stating its reasons. The members of the original panel (Judges Lourie, Prost, and Hughes), however, provided a seven-page opinion concurring in the denial of rehearing. As well as providing a vigorous defense of its original decision, the panel's opinion supporting the denial of rehearing provides important guidance on the claiming of a chemical or biological genus.

BACKGROUND

Amgen's patent claims at issue cover a genus of monoclonal antibodies that purportedly bind to the protein PCSK9 and lower low-density lipoprotein ("LDL") cholesterol levels by blocking PCSK9 from binding to LDL receptors. Like many other antibody patents, Amgen's claims were written in functional terms, requiring that, when bound to PCSK9, the antibodies (1) bind to at least one of a list of residues of a particular sequence, and (2) block binding of PCSK9 to the LDL receptors. After weighing the so-called Wands factors, the Federal Circuit panel held Amgen's patent specification "did not enable preparation of the full scope of these double-function claims without undue experimentation."² In its rehearing petition, Amgen argued that the panel had applied a new enablement test that "does not examine the effort required to find any embodiment, but the effort to find every embodiment."³ According to Amgen, this new test is legally unsupported because section 112 does not provide a "separate or heightened 'full scope of claimed embodiments' test for claims with functional limitations."⁴

REHEARING DENIAL

In their opinion concurring in the denial of Amgen's rehearing petition, the original Amgen panel members stated that they had not created a "new" test for enablement, commenting that a genus claim has always had to be "enabled by a disclosure commensurate with the scope of the genus."⁵ Where such genus claims cover compositions not actually reduced to...