Patent protection of living organisms, or substances derived from them, has long been a locus of confusion and controversy in law. Recently, however, there has been something of a move towards consensus on the boundaries of what constitutes patentable subject matter where life is concerned.

In the case Association for Molecular Pathology v. Myriad Genetics, the US Supreme Court definitively held that "A naturally occurring DNA segment is a product of nature and not patent eligible merely because it has been isolated." The Supreme Court decision was similar to the position ruled in Australia, where the Australian High Court unanimously found that isolated genetic material is not patentable.

By contrast, the patentability of isolated genetic sequences is expressly recognised under European law. Article 5 of the EU Biotechnology Directive provides that: "An element isolated from the human body or otherwise produced by means of a technical process, including the sequence or partial sequence of a gene, may constitute a patentable invention, even if the structure of that element is identical to that of a natural element' provided that the industrial application of such sequence is disclosed in the patent application". However, "[t]he human body ... and the simple discovery of one of its elements, including the sequence or partial sequence of a gene, cannot constitute patentable inventions."

In South Africa, our Patents Act specifically excludes certain subject matter from patentability. This includes "a method of treatment of the human or animal body by surgery or therapy or diagnosis practiced on the human or animal body". A drug, device or instrument for performing such a method of treatment is, however, still patentable in our law.

The Act also excludes "any variety of animal or plant or any essentially derived biological process for the production of animals or plants, not being a micro-biological process or the product of such a process." Here, however, we have neither case law nor directives to guide us as to what constitutes an 'essentially derived biological process'. Similar uncertainty currently clouds the meaning of what a 'micro-biological process or the product of such a process' might refer to.

Even with all this legal uncertainty regarding the exclusions on patentable subject matter in our law, a few guidelines can be postulated. Gene sequences, for instance, are probably patentable in our law, and almost certainly so if they are not slavish copies of naturally occurring nucleotide sequences. Similarly, biomolecules derived from natural sources (i.e. antibodies, enzymes and the like) are most likely patentable so long as they are isolated and characterised for a specific use. This accords well with our existing approach to drugs derived from plant or animal extracts.

Microbes are also patentable in our law, although where to draw the line at what constitutes a 'microbiological process' or a product thereof will undoubtedly remain a bone of contention for the foreseeable future. A substantial grey area thus exists as to whether a genetically modified, fertilised plant or animal egg, embryo or cell culture is patentable. Here the line may well be drawn at whether the specific method of the invention may be characterised as an in vitro one, or whether the invention requires an in vivo step that could reasonably be characterised as being an 'essentially biological process' to produce a plant or animal.

It is fairly well agreed upon that tissues and organs isolated from humans or animals may be patentable in certain contexts (including methods of surgery, therapy or diagnosis) as these do not constitute the human or animal 'body' referred to in the Act. Read with the proviso related to drugs, devices and instruments, this leads to the conclusion that removal and culturing of cells for the purpose of surgery, therapy or diagnosis is patentable even where their subsequent reintroduction (as in CAR-T therapies) is by itself not.

Finally, the Act clearly draws the line at the patenting of 'varieties' of animals or plants. This has led to a long-standing issue where genetically modified hybrid crops (which would ordinarily be protected under the aegis of plant breeder's rights) are excluded from patent and from becoming protected varieties for technical reasons. The result is a rather clumsy work-around where the parent lines of the hybrid are protected via plant breeder's rights and the genetic constructs used to make it (as well as any accessory microorganisms used in the process) are protected under patents. Something similar may hold with genetically modified animals such as knock-out mice – with the mice themselves being non-patentable but the genetic constructs and/or the processes used to produce them being acceptable subject matter for protection.

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