The EPO Board of Appeal (“BoA”) recently rejected a patent application relating to pig-human chimeras, concluding that the invention was contrary to morality and offensive to human dignity.

The application

The claims involved methods for generating pig-human chimeric animals. Essentially, human stem cells are introduced into a pig embryo, with the ultimate aim of using these pig-human chimeras as a source of human vasculature and blood.

Relevant Provisions

The following provisions on exclusions from patentability were at issue in this case:

1. Article 53(a) EPC: prevents the patentability of inventions which would be contrary to “ordre public” or morality if commercially exploited.
   
    
2. Rule 28(1) EPC: lists examples that would fall under Article 53(a) EPC, including for example “processes for cloning human beings”, “processes for modifying the germ line genetic identify of human beings” and “processes for modifying the genetic identity of animals which are likely to cause them suffering without any substantial medical benefit”.
   
    
3. Recital 38 EU Biotech Directive: states that an example of a process which would “offend against human dignity” includes “processes to produce chimeras from germ cells or totipotent cells of human and animals” (emphasis added).

The Applicant’s Arguments

One of the applicant’s main arguments centred around Recital 38’s reference to totipotent cells. The applicant argued that, as the application involved the use of only pluripotent rather than totipotent cells, it was not specifically excluded under Recital 38.

The BoA’s Decision

The BoA considered the distinction between totipotent and pluripotent cells. It noted that:

• Totipotent cells are capable of “form[ing] an entire organism” and, in a chimera, “may form a brain with human-like cognitive abilities or human germ cells.” 
• Pluripotent cells, on the other hand, “lack the ability to differentiate into totipotent cells or cells of the placenta, but nevertheless have the ability to differentiate into neural cells or germ cells.” 

It is important to note that what constitutes a ‘pluripotent’ cell versus a ‘totipotent’ cell is not, at least from a scientific position, clearly defined and there is ongoing debate regarding their precise understanding.

Regardless of these perceived differences, the BoA held that the underlying rationale of Recital 38 still applied to pluripotent cells and therefore the application in issue. The key ethical issue was the risk of the human cells integrating into the chimera’s brain (potentially giving the chimera human-like cognitive capabilities) or into its germ line (potentially giving it the ability to pass on humanised traits). The BoA emphasised that these concerns were not merely hypothetical but based on scientific evidence.

A particularly important factor in the decision was that the application failed to include methods of preventing the integration of the human cells into the brain or germ cells of the chimera. 

Despite acknowledging the importance of the invention, the BoA clarified that a balancing test between the medical benefit and the ethical concerns was irrelevant in this case. The invention fell squarely within the categories the legislator had expressly excluded from patentability ipso facto – meaning there was no room for manoeuvre. 

Key takeaways

This decision highlights the “object and purpose” approach to interpreting morality-based exclusions in patent law. The examples listed in the EPC and the EU Biotech Directive are not to be interpreted narrowly; rather, their underlying purpose must be construed. 

Where scientific evidence suggests ethical concerns could become a real possibility, steps should be taken to ensure patent applications include methods of preventing such concerns. Failure to do so could result in the application being rejected, regardless of the medical benefits the invention could ultimately bring.