Focusing on the genetic construct when applying for a drug patent could be key to obtaining protection

11 March 2021

This article was originally published by IAM Media

Russia has a lively pharmaceutical market, in which it is possible to obtain comprehensive patent protection for products and methods that are aimed at treating and diagnosing specific diseases. However, development in the sector relies on manufacturers being confident that their patents will provide adequate and reliable protection, which requires comprehensive patent protection for both the drug and for items in related fields. When drafting an application, it is therefore crucial to focus on aspects, such as genetic constructs.

General rules

Under Russian regulations, genetic constructs include plasmids, vectors, stably transformed cells of microorganisms, plants and animals and transgenic plants and animals, among other things.

The following features can be used to characterise genetic constructs:

  • an enhancer;
  • a promoter;
  • a terminator;
  • an initiation codon;
  • a linker;
  • a fragment of a foreign gene;
  • a marker; and
  • flanking regions.

For a transformed cell, the following features can be used:

  • a transforming element;
  • properties acquired by the cell;
  • an indication of the origin of the cell (for a prokaryotic cell – genus, family, and/or species);
  • taxonomic characters;
  • a mutation of the natural genome; and
  • cell cultivation conditions and other characteristics that are sufficient to distinguish this cell from another.

For a transgenic plant, the following features are used:

  • the presence of a modified element in the genome;
  • properties acquired by the plant;
  • the origin of the plant; and
  • the taxonomic affiliation and other characteristics sufficient to distinguish this plant from another.

For a transgenic animal, the following features are used:

  • a gene and/or DNA transformed into the animal's genome and encoding or expressing the target product;
  • properties acquired by the animal;
  • a modified product produced by an animal; and
  • the taxonomic affiliation and other characteristics sufficient to distinguish this animal from another.

Practical tips

Claims relating to a genetic construct should be restricted to the drug's purpose or biological function that determines this purpose. For example:

"A recombinant poliovirus vector designed to stimulate an immune response against a pathogenic microorganism, or a virus, or a target cell, having the formula C-B-A-B-C, where A is an exogenous nucleotide sequence"

In many cases, an essential feature characterising a transformed cell, transgenic plant or animal may be a product (eg, protein, polypeptide or peptide) that is expressed by the transformed nucleic acid that is introduced into the cell. In these cases, the purpose of the transforming element may not coincide with the purpose of the genetic construct or with the properties that it acquires as a result of transformation. Here, it is necessary to specify the purpose and/or properties of the genetic construct in the independent claim:"Host cell for expression of protein A, transformed with DNA set in SEQ ID NO: 1."

The most common type of genetic construct is a vector, which is a combination of genetic elements (ie, fragments of natural nucleic acids as found in an artificially created recombinant nucleotide sequence).

The main characteristic in defining a 'vector' is its ability to replicate autonomously after it has entered a cell. However, it can perform other functions – delivering agents to a target, ensuring the expression of a certain product, and integrating nucleotide sequences into the cell genome, among other things. Thus, in relation to a vector construct, the function that determines the purpose cannot be limited to the term 'vector' and should be specified as 'cloning', 'expressing' or 'for integration', among other descriptions.

In the case that ready-made carrier vectors are used, it may be sufficient to cite the trade name of the used vector with its disclosure in the description of the invention instead of providing detailed characteristics in the claims. For example, "Recombinant vector pSR alpha-20-2 for expression of a lipogenesis inhibition factor containing a 3.4 kb BamHI fragment of the pSDL-SR alpha 296 vector and 1.2 kb BamHI fragment containing the nucleotide sequence corresponding to SEQ ID NO X".

If the invention relates to a number of recombinant vectors, which contain a new element and disclosed in the description of the invention, then the following characteristic can be used: "Expression vector comprising a DNA fragment with a nucleotide sequence encoding polypeptide X, which is operably linked to regulatory elements that ensure the expression of said fragment in a Y cell."

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