Stem cell technologies are to be considered and examined in the same light as other technical inventions. These guidelines essentially clarify the patentability of stem cell technologies in relation to sec 18(2) and sec 50(1)(a) and do not remove the obligation to review applications involving these technologies for compliance with all other statutory requirements.

Stem Cells

Stem cells are cells with the ability to divide indefinitely in culture and the capacity to differentiate into other cell types.

A pluripotent stem cell is able to differentiate into any cell type in the body of the mature organism.
A multipotent stem cell has a more restricted differentiation potential compared with a pluripotent stem cell.
A totipotent stem cell has the ability to differentiate into any cell type of the species from which it is derived. Any human cell type, as well as a complete human being, is able to be generated from a single human totipotent cell.

Stem cells are further classified according to their tissue of origin.

Human Embryonic Stem Cells

Human embryonic stem cells are derived from the inner cell mass of the human blastocyst and are considered to be pluripotent because of their capacity to differentiate into cell types of mesodermal, ectodermal and endodermal lineages. Human embryonic stem cells are not considered totipotent because these stem cells or their differentiated derivative cells do not have the capacity to develop into an entire human being.

Given the interpretation of 'human being' set forth in Fertilitescentrum AB and Luminis Pty Ltd [2004] APO 19 [2004] APO 19, it follows that human stem cells and human stem cell lines per se are patentable because these cells are not considered to be human beings or potential human beings within the meaning of sec 18(2).

Human embryos, however, are considered to be human beings within the meaning of sec 18(2). Consequently, human embryos and processes for generating or culturing human embryos for any purpose, including the harvest of stem cells, are not patentable. The exclusion extends to all means of generating human embryos and includes generation of embryos by nuclear transfer, altered nuclear transfer, activation of gametes and parthenogenesis.

Human Adult Stem Cells

Adult stem cells are derived from various postnatal and adult tissues such as cord blood, bone marrow, adipose tissue and neural tissue. There are some reports of pluripotent adult stem cells, however the majority of adult stem cells appear to be multipotent in that they have the capacity to develop into cells of only one or two of either the mesodermal or ectodermal or endodermal lineages. These stem cells do not have totipotent capacity to generate a human being.

As adult stem cells are derived from non-embryonic tissues, both adult stem cells per se and processes for their isolation from non-embryonic tissues and organs are patentable with respect to sec 18(2).

Human Totipotent Stem Cells

A totipotent cell can be derived from fertilised oocytes and cells of an embryo up to about the 8 cell stage, and have the inherent capacity to generate an entire human being. Consequently, these cells and methods or processes of obtaining human totipotent cells are not patentable under sec 18(2).

Human/Non-Human Hybrid Totipotent Cells and Stem Cells

The provisions of sec 18(2) relate only to human beings and methods of their generation. Consequently, non-human cell types and methods of their isolation from non-human animals are patentable.

A question arises however, as to the patentability of cells derived from inter-species hybrids or chimeras. In Woo-Suk Hwang [2004] APO 24 [2004] APO 24, it was considered that the presence of human nuclear DNA in a cell is sufficient to confer 'human being' characteristics on the cell. It follows that if totipotent cells were or could be derived from inter-species hybrids with 'human being' characteristics, the cells and the methods of their generation would not be patentable.

Stem cells derived from inter-species embryos with 'human being' characteristics are considered to be human stem cells and are patentable, however all processes for the generation and culture of the inter-species embryo are not patentable under sec 18(2).

Relevance of Subsection 50(1)(a)

Under sec 50(1)(a), a patent may be refused if the invention is contrary to law. In some cases, inventions relating to stem cells derived from human embryos may be in breach of the Prohibition of Human Cloning for Reproduction Act 2002 and/or the Research Involving Human Embryos Act 2002. The legislation includes the provision that a human embryo may only be created by fertilisation of a human egg by a human sperm, and that it is an offence to create embryos by other means, for example by combining cells or cellular material from a human and another species or by cloning embryos. In situations where the process or method for generating human embryonic stem cells appears to contravene either the Prohibition of Human Cloning for Reproduction Act and/or the Research Involving Human Embryos Act, an objection under sec 50(1)(a) is to be taken.