In the latest development in global patent litigation that has polarised the life sciences industry, Amgen’s patent claims covering a whole class of monoclonal antibody PCSK9 inhibitors have been ruled to be invalid by the US Court of Appeals for the Federal Circuit.
The US patents cover Amgen’s own antibody evolocumab (branded as Repatha), which is used as a cholesterol medication, and the structurally distinct rival antibody alirocumab (branded as Praluent), which Sanofi and Regeneron developed independently.
This article considers:
- That Amgen’s original patents were broad enough to cover antibodies that it had not actually invented because the patent claims defined the antibodies in broad functional terms, rather than in terms of their molecular structure
- Whether the patent claims met the statutory test for ‘enablement’, essentially the requirement that the patent’s specification must ‘enable any person skilled in the art…to make and use’ the patented invention
- Amgen’s case, that a skilled practitioner could make all antibodies within the scope of the claims by following a ‘roadmap’ involving routine screening techniques described in the specification, or by making minor modifications to the twenty-six examples described structurally
- Sanofi’s case, that there are millions of antibody candidates within the scope of the claims and that undue experimentation would be required to make and test them to determine whether they satisfy the claimed functions.
- The key arguments from both sides
- The court’s reasoning behind its decision, which aligns the allowable scope of antibody patents with the small molecule case law
- The fate of equivalent patents outside the US
- The implications for the life sciences sector.
