Fed Circuit refuses Amgen unit appeal in win for Sanofi

The US Court of Appeals for the Federal Circuit has dismissed Immunex’s appeal against a decision invalidating its patent on treating inflammatory disorders.

In a win for Sanofi and Regeneron yesterday, October 13, the Federal Circuit concluded that the Patent Trial and Appeal Board (PTAB) was correct to invalidate the claims of US patent number 8,679,487.

Sanofi and Regeneron had been accused of infringing the patent, which covers isolated human antibodies that bind the human interleukin-4 receptor, through the sale of eczema and asthma treatment Dupixent (Dupilumab).

In response, Sanofi and Regeneron challenged the patent through two inter partes reviews (IPRs).

The board invalidated all challenged claims in one of the IPRs, which Amgen’s unit Immunex appealed against, contesting the construction of the claim term “human antibodies”.

In the other IPR, which involved a subset of the same claims, the board didn’t invalidate the patents for reason of inventorship. Sanofi appealed against this but, as the Federal Circuit affirmed the invalidity decision, Sanofi’s appeal was dismissed.

In yesterday’s precedential ruling, the Federal Circuit rejected Immunex’s argument that the PTAB erred by construing the term “human antibody” to encompass not only “fully human” but also “partially human” antibodies.

“Immunex, disagreeing that ‘fully’ was necessary to convey an antibody’s ‘completely human’ nature, quotes approvingly a district court’s remark in the accompanying litigation that ‘when one purchases . . . a German Shepherd, one assumes, absent further context, that the seller will not deliver . . . a poodle-Shepherd mix’,” said the court in a footnote.

It added: “But to the extent that canine metaphors are apt, more on the nose is that ‘brown dogs’ plainly include ‘partially brown’ dogs, such as a mostly brown dog with a white spot.”

Turning to the prosecution history, the Federal Circuit added that it agreed with the board that nothing indicates that Immunex added “human” to limit the scope to fully human.

“There was no apparent need to do so in light of the rejection, and no evidence that anyone understood Immunex to be casting aside subject matter that was not at issue,” said the court.

It affirmed the board’s invalidity judgment holding the ‘487 patent invalid as obvious.

A spokesperson for Sanofi said that both it and Regeneron were pleased with the Federal Circuit’s decision.

“It has been our longstanding belief that Immunex’s asserted patent claims are invalid, and the decision by the Federal Circuit confirms that the law and facts support our position,” they added.

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