http://ipkitten.blogspot.com/2025/01/board-of-appeal-finds-that-humanpig.html
A recent EPO Board of Appeal decision considered the patentability of human-animal chimeras and where the line should be drawn on moral acceptability (T 1553/22). The Board of Appeal found that the invention in question was an offence against “human dignity” given that the scope of the claims included scenarios in which human cells could integrate into the the brain or germ-line of the chimeric animals specified in the claims. The decision provides important guidance on how the morality exclusion under Article 53(a) EPC should be interpreted in the context of biotechnological inventions involving human-animal chimeras.
Moral jeopardy of stem cell technologies
The patent application at issue in T 1553/22 related to methods for producing human-pig chimeras designed to generate humanised blood vessels and blood cells for therapeutic applications (EP16759528.9, Regents of the University of Minnesota). The claimed method involved creating gene-edited pig embryos lacking a gene essential for blood vessel and blood cell development (ETV2 gene). The modified pig embryos could then serve as hosts for human stem cells, which could go on to create human blood and blood vessel components within the pig. The application as filed included data demonstrating the successful deletion of ETV2 in pig embryos, integration of human pluripotent stem cells (PSCs) into the pig embryo and the formation of humanised blood vessels in the developing chimeric embryos.
In the application as filed, the applicant proposed that the invention would help address the critical shortage of organs for transplantation by providing a source of humanised tissues that could match a patient’s genetic makeup. The system could, for example, generate human blood vessels for transplantation, provide human blood cells for treating various blood disorders, serve as a platform for studying human blood vessel development, and create animal models for testing drugs that affect blood vessels.
Legal Background: Protecting human dignity
Article 53(a) EPC excludes from patentability “inventions the commercial exploitation of which would be contrary to ‘ordre public’ or morality.” Article 53(a) EPC is supplemented by Rule 28(1) EPC, which provides a non-exhaustive list of excluded inventions, including processes for cloning human beings, modifying the human germ line, and using human embryos for commercial purposes. Additionally, Recital 38 of the EU Biotech Directive (Directive 98/44/EC) (which provides supplementary means of interpretation under Rule 26(1) EPC) specifically states that “processes, the use of which offend against human dignity, such as processes to produce chimeras from germ cells or totipotent cells of humans and animals, are obviously also excluded from patentability”.
The interpretation of Article 53 EPC has been the subject of several referrals to the Enlarged Board of Appeal (EBA), including G 2/06 (WARF/Stem cells) and G 2/12 (Tomatoes II/Broccoli II). Both of these decisions emphasised that exclusions from patentability must be interpreted in light of their object and purpose, rather than by automatically applying a narrow interpretation of the legal text.
The patentability of human-pig chimeras
The patent application (EP16759528.9, Regents of the University of Minnesota) related to methods of producing pig-human chimeric animals expressing humanised vasculature and blood. The claims at issue on appeal specifically related to a chimeric non-human cells expressing the human protein ETV2 and a chimeric non-human animal expressing containing human blood cells. On appeal from the decision of the Examining Division to refuse the application, the applicant argued that, since the claimed invention used pluripotent rather than totipotent stem cells, it fell outside the specific exclusion in Recital 38 of the EU Biotech Directive.
Pluripotent and totipotent cells differ in their developmental potential and stage at which they appear during embryo development. Totipotent cells are found in the very early embryo and have the potential to generate all cell types in an organism, including both embryonic tissues and extraembryonic tissues (such as the placenta). In other words, a totipotent stem cell has the capacity to create an entire organism. In contrast to totipotent cells, pluripotent stem cells appear slightly later in development. Whilst pluripotent cells can give rise to all cell types within the embryo, they cannot form extraembryonic tissues, including the placenta and its supporting tissue. This means they can generate any cell type in the adult body but cannot alone create a complete organism since they cannot form the placenta. In other words, totipotent cells can form all cell types including both the embryo and its supporting structures, whilst pluripotent cells can form most cell types but specifically those within the embryo itself. Chimeric totipotent cells, capable of producing an entirely new organism in full, therefore represent a greater moral hazard than pluripotent stem cells.
The Board of Appeal decision
| Kat-pig |
Following the approach of the EBA on issues of patentability exclusions, the Board of Appeal first established that, whilst Recital 38 of the EU Biotech Directive specifically related to chimeras produced from totipotent cells, its underlying rationale could extend to other types of chimeras where similar ethical concerns arise. According to the Board of Appeal “the reason why the chimeras identified in Recital 38 are regarded as offensive against human dignity is due to concerns that, in chimeras including human germ cells or totipotent cells, these human cells may integrate into the brain and/or develop into germ cells and result in a chimera with human or human-like capabilities” (r. 22). Therefore, for the Board of Appeal, “if an invention relates to a situation where human cells might integrate into the chimera’s brain, potentially giving the chimera human-like cognitive or behavioural qualities, or into its germ line, potentially giving it the ability to pass on humanised traits”, the Board of Appeal considered the underlying rationale of Recital 38 of the Directive would be relevant.
The Board of Appeal was also convinced by evidence that such concerns were not merely hypothetical. The Board of Appeal noted scientific evidence that pluripotent stems cells could contribute to the development of tissues including neural cells or germ cells within chimeras. Crucially for the Board of Appeal, the claims at issue also did not include any technical features that would prevent the human cells introduced into the pig embryo from integrating into the brain or germ cells of the chimeric animals. The Board further found that the benefits to society of the potential therapeutic applications of the invention were not sufficient to overcome the moral hazard.
Final Thoughts
In T 1553/22, the Board of Appeal provided an outline for assessing chimeric stem cell inventions under Article 53(a) EPC. The Board particularly emphasised that the morality exclusion to patentability extends beyond the specific examples mentioned in Recital 38 of the EU Biotech Directive to encompass situations where similar ethical concerns arise.
The decision is also notable for its adherence to the “object and purpose” approach to interpreting exclusions from patentability. The Board of Appeal explicitly rejected the argument that the exclusions provided for in the EPC and EU Biotech Directive should be interpreted narrowly, citing G 2/12 and emphasising that such interpretation must be guided by the underlying purpose of the provision.
This case is also a reminder that, for inventions that risk crossing the line of moral unacceptability, careful claim drafting is key. It is crucial for applicants to ensure that the application as filed contains sufficient basis for specifically exclusion of unwanted scenarios. For example, when drafting claims involving human-animal chimeras, attention must be paid to including technical features that would prevent human cells from integrating into “ethically sensitive” tissues such as the brain and germ-line cells that might give rise to a chimera with human or human-like capabilities.
The decision also raises interesting questions about the relationship between patent law, regulatory approval and medical advances. While the Board acknowledged the potential medical benefits of the invention in question, they also made it clear that such considerations cannot override fundamental ethical lines encoded into European patent law to preserve human dignity. The decision in T 1553/22 therefore makes an interesting contrast to another recent decision in which a moral issue (in this case the morality of an invention derived from traditional remedies by dishonest means), was not considered to be in the purview of the EPO (IPKat).
Further reading
The morality (and patentability) of inventions derived by immoral means (T 2510/18) (Oct 2024)
Image credit: Midjourney
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