Genentech to face revived Hemlibra claims

Genentech and  Chugai Pharmaceutical will have to face claims that its haemophilia drug Hemlibra (emicizumab-kxwh) infringed a patent owned by  Takeda subsidiary Baxalta.

In an  opinion issued yesterday, August 27, the US Court of Appeals for the Federal Circuit overturned a lower Delaware court’s ruling in favour of Genentech.

According to the Federal Circuit, the US District Court for the Delaware misconstrued the construction of two key terms of Baxalta’s patent when dismissing the lawsuit.

The district court will now have to re-hear Baxalta’s case under the Federal Circuit’s revised claim construction.

In the Delaware proceedings, Baxalta and Genentech clashed over the correct construction of the terms “antibody” and “antibody fragment”.

The district court opted for Genentech’s narrower definition and ruled that the company had not infringed the patent on those terms.

But according to the Federal Circuit, the district court’s construction was inconsistent with the “plain language” of the patent.

The district court recognised this problem, but said this should lead to the “invalidation of the inconsistent claims rather than an expansion of the independent claims”.

The Federal Circuit disagreed, finding that: “The plain language of these dependent claims weighs heavily in favour of adopting Baxalta’s broader claim construction.”

Baxalta sued Genentech and Chugai in 2017, seeking an injunction blocking the companies from developing and marketing Hemlibra in the US.

Baxalta, and its former parent company Shire, were absorbed into Takeda Pharmaceutical in a 2019 merger.

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