Fed Circ written description ruling overturns $1.2 billion award
Kite Pharma has successfully persuaded the US Court of Appeals for the Federal Circuit to reverse a $1.2 billion win for the Bristol-Meyer s Squibb owned Juno Therapeutics over a cancer treatment patent.
The three-judge panel unanimously ruled that claims of US patent 7,446,190 were invalid, backing Kite’s argument that “no reasonable jury” could find the patent’s written descriptions sufficient.
Kite’s argument centred on a type of binding element in the patent, a single-chain antibody variable fragment (scFv) that specifically targets and binds a protein known as CD19.
According to Kite, the written descriptions did not satisfactorily describe which scFv would function like this, and claimed that the ‘190 patent description “cover[s] an enormous number, (millions of billions) of scFvs”.
The court said: “Juno’s general testimony about general scFv structure does not provide substantial evidence regarding the claims containing the functional limitation that covers all scFvs that bind to CD19.”
The court concluded: “Without this guidance… no reasonable jury could find the ’190 patent satisfies the written description requirement.”
The dispute arose when Juno sued Kite for copying the cancer treatment. Later, Kite would release Yescarta, a CAR-T cell therapy used to treat large B-cell lymphoma.
In April 2020, the US District Court for the Central District of California awarded $1.2 billion to Juno and the Sloan Kettering Institute, after a jury found that Yescarta infringed the ‘190 patent.
This is the latest in a line of Federal Circuit decisions covering written description and enablement requirements of 35 USC §112. These decisions have left antibody practitioners “uncertain” about just how much support is required in a patent application, according to Benjamin Pelletier, partner at Haynes & Boone.
In February this year, the circuit ruled on Amgen v Sanofi, finding that the functional claims of two Amgen antibody patents were too broad. This decision was criticised by GlaxoSmithKline (GSK) in an amicus brief which claimed that the ruling could “threaten” innovation.
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