Amgen appeals against PTAB Sanofi decision

Amgen subsidiary Immunex has appealed against a Patent Trial and Appeal Board (PTAB) decision which invalidated a patent claiming antibodies that target human interleukin-4 receptors (IL-4R).

Immunex filed its appeal at the US Court of Appeals for the Federal Circuit on Wednesday, April 10, two months after the PTAB invalidated all the claims of a patent that Immunex had accused Sanofi-Aventis and Regeneron of infringing.

In March 2017, Sanofi-Aventis and Regeneron filed a petition for inter partes review (IPR) of the US patent, number 8,679,487, but this petition was rejected by the PTAB.

The following month, Immunex accused Sanofi-Aventis and Regeneron of infringing the patent with the biologic Dupixent (dupilumab) in a claim filed at the US District Court for the Central District of California. This case was stayed pending appeal of the PTAB decision.

Dupixent is a targeted biologic therapy that binds to IL-4R and inhibits signalling of IL-4 and IL-13, two proteins that play a central role in type 2 inflammation that underlies many allergic diseases.

In July 2017, Sanofi-Aventis and Regeneron filed another two petitions for IPR of the patent, alleging that the claims of the patent were obvious in light of prior discoveries by two other inventors.

While one of the IPRs was terminated in February 2019, the PTAB found in favour of Sanofi-Aventis and Regeneron in the other.

In mid-February, the PTAB invalidated all 17 claims of Immunex's patent as obvious.

That same month, the European Patent Office revoked Immunex's European patent number 2,990,420 in its entirety because the claims were invalid for insufficiency of disclosure.

At the time, Joseph LaRosa, executive vice president and general counsel of Regeneron,  said: “It is our position that Immunex's functional claims unfairly attempt to claim ownership far beyond the molecules developed, and stifle innovation within the broader scientific community.”

In a comment provided to LSIPR, a spokesperson for Sanofi-Aventis said: “It is our longstanding belief that Immunex’s asserted patent claims are invalid, and we are confident that the law and facts support our position.”

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