What are stem cells and why are they so important?

The body is an amazing thing, made up of billions of cells of many different, specialised types, to carry out all the functions and requirements of a complex organism. Brain cells, muscle cells, skin cells, blood cells - the list goes on and on.

However, the body starts out as a single cell – a fertilised egg called a zygote. The zygote then starts to divide, forming 2, 4, 8, 16 cells, etc., becoming an embryo. Before the embryo implants in the uterus, it is a mass of around 150–200 cells called a blastocyst, having an outer mass of cells that forms the placenta and an inner mass of cells that eventually generate all the specialised cell types to form the body.

Stem cells are non-specific cells that are capable of self-renewal (dividing to increase their number) and are capable of differentiating, i.e. developing into various types of specialised cells. Their classification is typically based on the extent to which they may differentiate into different types of cells, as follows:

Totipotent stem cells can differentiate into all possible cell types of an organism. Embryonic cells within the first few divisions, as the zygote starts to divide, are totipotent.

Pluripotent stem cells can differentiate into most (but not all) cell types. Cells from later divisions in the early embryo are pluripotent.

Multipotent stem cells can differentiate into a limited group of closely related types of cells. Hematopoietic stem cells, for example, can become red and white blood cells or platelets.

Stem cells may also be classified based on their origin. Totipotent and pluripotent stem cells, which may be obtained from an embryo, are also referred to as embryonic stem cells. Adult stem cells are multipotent.

With the evolution of biotechnology and cell culture methods, stem cells can be induced to develop into various specialised cell types of interest. They may thus be used to generate new cells and tissues for any situation in which cells are deficient, for example, to replace damaged or deteriorated tissue or to generate new tissue for a specific purpose. For example, hematopoietic stem cells can be transplanted into the bone marrow of cancer patients to increase their ability to produce red and white blood cells and platelets, which is now standard treatment in certain cancer patients. Thus, this unique ability to develop into specialised cells makes stem cells very important in medical research and a variety of therapeutic applications, such as regenerative medicine.

Stem cells and patenting around the world

Due to their very nature, stem cells present unique issues when it comes to patenting, that may vary significantly between jurisdictions:

Stem cells are living matter

Certain jurisdictions have particular exclusions concerning the patentability of living matter. For example, Argentina, Colombia, Denmark and India have certain statutory exclusions relating to the patenting of living matter. Note that this relates to claiming certain types of stem cells per se. For example, a method of producing stem cells may be patentable whereas a claim to the product itself may not.

Stem cells may be obtained from nature

This is notably an issue in the US, where the Myriad[1] decision has created an exclusion to the patentability of products of nature.

Such exclusions may typically be addressed by claiming a stem cell which is somehow removed from or isolated from its naturally occurring state. However, in some cases, if the isolated cell is not sufficiently different from its naturally occurring counterpart, this may still be a bar to patentability.

Stem cells may be obtained from humans

Given the potential for therapeutic applications in humans, human stem cells are of great importance. Key issues here relate to how the stem cells are prepared and to what extent they can differentiate into other cell types.

Some countries have a statutory exclusion relating to any stage of the development of the human body. For example, in Switzerland, UK and Portugal, any stage of human body formation is excluded from patentability.

Stem cells may be obtained by different processes

First, there is sometimes a requirement that the stem cell is obtained by some level of human intervention/laboratory manipulation. If the only steps involved relate to purely biological processes, it may create an exclusion from patentability.

Second, stem cells may be obtained from fertilised human embryos.  Human embryonic stem cells (hESCs) were originally obtained from human embryos fertilised in vitro, that are no longer needed for fertilisation (in vitro fertilisation procedures, several fertilised embryos are prepared but not all are used). This means that obtaining hESCs may involve the destruction of fertilised embryos. In such a case, particularly if their preparation necessarily involves the destruction of fertilised human embryos, there may be a bar to patentability. For example, Rule 28(1)(c) of the European Patent Convention (EPC) sets forth an exclusion of the uses of human embryos for industrial or commercial purposes. The exclusion of stem cells from patentability if their preparation involves the destruction of fertilised human embryos is seen in several EPC member states (Austria, Spain, Switzerland, Ireland, Germany, Portugal, Turkey) as well as Mexico and Singapore.

Over the years, techniques have been developed to obtain hESCs without destroying fertilised human embryos, and therefore a time component may be relevant: What was the state of the art in this regard when the patent application was filed? Was the destruction of fertilised human embryos absolutely necessary to obtain hESCs at that time?

Two cases of the Court of Justice of the European Union (CJEU) are of particular interest in this regard. The Brüstle[2] decision established that an invention involving the destruction of a human embryo cannot be patented. However, in the later decision of International Stem Cell Corporation[3], stem cells derived from an unfertilised human ovum whose division and further development have been stimulated by parthenogenesis were not considered an “embryo”, thus removing this exclusion if the process did not require the destruction of a fertilised human embryo.

In some cases, a time cut-off is defined, for example excluding the use of an embryo after a certain number of days post-fertilisation. For example, China and Singapore exclude the patentability of stem cells prepared using a human embryo that has been fertilised more than 14 days.

Certain types of stem cells are capable of developing into all the cell types of an entire animal

This brings into play exclusions relating to patenting animals or higher life forms, at any stage of their development. Another statutory exclusion relates to any stage of the development of the human body. For example, in China, living matter that can become an animal is excluded from patentability.

Some countries, such as Canada, UK, China, Mexico and India, exclude totipotent stem cells from patentability, whereas for example adult stem cells and pluripotent and multipotent stem cells are acceptable.

Ethical and moral issues

As can be appreciated, given all the above, ethical or moral issues may come into play, particularly in respect of human stem cells, some of which are specifically addressed in patent laws.

Many countries (Argentina, Austria, Switzerland, China, Germany, Spain, UK, Greece, India, Mexico, Malaysia, Portugal, Singapore, Turkey, and South Africa) have a specific provision under which inventions which may threaten public order or morality are not patentable. However, certain types of stem cells are still considered patent eligible in some cases.

Stem cell claiming strategies

As in most areas of patenting, different categories of claims may be considered in this regard, such as:

  • Stem cells (e.g. based on the presence/absence of biomarkers, functional properties (e.g. behaviour in culture, potential for differentiation, etc.), source/method of preparation).
  • Methods of preparing stem cells
  •  Methods of using stem cells or alternatively “use” and “product for use” formats, such as Swiss and German-style use claims and EPO-style first and second medical uses

Further to the above, acceptable subject matter and in turn claim formats vary between jurisdictions.

It’s complicated!

It’s clear that when it comes to patenting, stem cells present several unique issues, which when considered/interpreted by the patent and legal systems of different countries, results in a broad range of practices in this regard. However, with advances in technology and patent laws, a number of options are available for patenting such subject matter in different jurisdictions.

Next steps

FICPI’s view and involvement 

  • FICPI is the only organisation exclusively for independent IP attorneys. The organisation uniquely combines education and advocacy on topics around patents and trade marks, with a focus on developing the professional excellence of its individual members. FICPI brings independent IP attorneys around the world together to connect, share knowledge and grow. 
  • Events such as FICPI’s 2023 Open Forum (4-7 October, London) offer the opportunity to attend technical sessions, and to meet and further discussions in congenial surroundings.


[1]Association for Molecular Pathology v. Myriad Genetics, Inc., 569 U.S. 576 (2013).

[2]Oliver Brüstle v Greenpeace, CJEU, Case C-34/10.

[3]International Stem Cell Corporation v Comptroller General of Patents, Designs and Trade Marks, CJEU, Case C‑364/13.