Following the (in)well-known Amgen v. Sanofi choice, which has declared invalid generic antibody claiming for failure to allow the full scope of the invention, antibody purposes drafted in the United States deal with structural characterization by complementarity-determining areas and variable domains. However, purposeful antibody claiming affords a broader scope of safety and financial effectivity by bundling a number of antibodies below the roof of a standard property, which is of nice curiosity to firms growing therapeutic antibodies.

Defining an antibody by its epitope is one kind of purposeful antibody claiming, which got here into the limelight in Europe when Amgen’s PCSK9 epitope claims have been challenged in a number of EPO oppositions. While Amgen managed to keep away from a probably adverse Board of Appeal choice on epitope claims in the first opposition towards EP 2215124 by narrowing the claims to structurally outlined antibodies (T 845/19), epitope claims of the divisional patent EP 3666797 are presently being challenged in an ongoing opposition in addition to earlier than the UPC. The choice of the Munich Central Division of the UPC of 16 July 2024 (UPC 1/2023) rejecting the epitope claims garnered a lot consideration as one in every of the first UPC choices on the deserves. 

On the background of the Amgen saga and of the current choice in T 435/20 rejecting as inadequate a declare to IL-23 antibodies outlined by a conformational epitope, the choice in T 326/22 taken in the oral proceedings on August 1 this 12 months is a welcome sport changer. The Board of Appeal confirmed that epitope claiming, particularly conformational epitope claiming, is legitimate, offered the patent incorporates enough data on antibody era.

The underlying case EP 2812443 involved CD47 antibodies characterised by their binding to a conformational epitope outlined by its sequence utilizing open “comprising” language. The insufficiency objection was based mostly on an alleged undue burden related to de novo manufacturing of antibodies binding to a conformational epitope. The opponent emphasised the “elite occasion” nature of antibody era by such classical strategies as hybridoma or phage show, in addition to the want for laborious X-ray crystallography (“XRC”)-based epitope screening. The board, nonetheless, disagreed, confirming the EPO place that producing antibodies to a particular antigen in addition to epitope willpower, particularly by XRC, is a routine, albeit time-consuming, train. 

This choice offers a great addition to epitope claiming in Europe. Applicants ought to be mindful the benefits of epitope claims when drafting patent purposes.

Jones Day represented the patentee in T 326/22.