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Patent Considerations in the Immunotherapy Space: Support and Enablement

Market analytics reveals that the global antibody therapy market revenue is expected to surpass USD $450 billion by 2028, which by comparison is more than double that of the global market value of approximately USD $180 billion back in 2021. Such growth in the global market is driven predominantly by research in the therapeutic space, as well as the unfortunate rising prevalence of chronic diseases, such as autoimmune disorders and cancers, which in turn increases the demand for novel drug therapy treatment, including for immunotherapies. Antibodies have been of growing interest as a form of biotherapeutic treatment, as they can target aberrant cells with impressive precision, which allows for selective antigen binding whilst offering a significant reduction in any off-target effects. Given that the first monoclonal antibody was approved by the US Food and Drug Administration (FDA) almost three decades ago back in 1986, needless to say, growth of the immunotherapy industry since then has been astounding.

Patent applicants in this area are often faced with challenges in obtaining a commercially appropriate scope of protection for their antibody inventions. There are a number of considerations that should be taken into account when trying to obtain the broadest possible scope of protection. This article provides some guidance around patenting antibodies in the Life Sciences space, highlighting some key issues that may be faced by international patent applicants when seeking to obtain patent protection in Australia, Europe and in the US. 

Firstly, we discuss some of the general considerations in relation to support and enablement in these jurisdictions:

Support and enablement in Australia

The “Raising The Bar” (RTB) reforms in 2012 amended the Patents Act 1990 (Cth), such that the requirements for patentability in Australian practice were brought closer in line to other major jurisdictions such as Europe, UK and the US. The support requirements post-RTB states that the claims must be “clear and succinct and supported by the matter disclosed in the specification”, which replaces the previous requirements of “fair basis”, under which support was found to be satisfied, if the claims are broadly directed to the invention described by the patent specification, as a whole.

However, at present, there has yet to be established precedence in Australian case law to help guide Applicants around the permitted scope of antibody protection in Australia.

Support and enablement in the US

In the US, on the other hand, case law in the area of antibody protection has been growing since 2014.

The written description criteria in the US requires an Applicant to experimentally demonstrate possession of a claimed genus through a disclosure of a representative number of species, by providing disclosures on relevant characteristics whether these are physical or physiochemical properties, in addition to disclosing functional characteristics of the antibody.

A claim is considered to enable a person skilled in the art to produce the claimed invention if the disclosure does not require substantial time and effort on the part of the skilled person to produce the antibody as claimed, in relation to the non-conservative variants (MorphoSys AG v Janssen Biotech, Inc. 358 F. Supp.  3d 354, 370-72 (D. Del. 2019)).

The case of Amgen Inc v Sanofi 987 F.3d 1080 (Fed. Cir. 2021) has been of much interest in the US, whereby it was held that Amgen’s antibody claims directed to a genus of therapeutic antibodies, lacked enablement, as they were defined by specific functional properties that allowed binding to specific amino acid residues of PCSK9 and which block binding of PCSK9 to LDL receptors. This decision represented a turning point in light of the Federal Circuit abolishing the “newly characterized antigen test”, which had previously allowed claims that were directed to a genus of antibodies, if the structure of the corresponding antigen has been sufficiently described. Crucially, the case of Amgen Inc v Sanofi held that determination on whether or not there is “undue experimentation” depends on a number of considerations (“Wands factors”), which relate to at least (i) the amount of experimental data, (ii) the number of working examples (iii) the details provided in  the specification, (iv) the nature of the invention, (v) the state of the prior art, (vi) the predictability or lack of in the art, and (vii) the breadth of the claims (re Wands, 858 F.2d 731, 737 (Fed. Cir. 1988).

With respect to item (vi), unpredictability in the art took into consideration that it cannot be predicted which antibodies could bind to PCSK9 and where, based on antibody sequence alone, without a person skilled in the art investing significant time in undertaking trial and error or extensive screening and in the absence of sufficient guidance in the specification. This is because potentially hundreds of candidate antibodies might fall within the scope of the functional claims.

The Federal Circuit Court’s decision in this case was unanimously upheld by the Supreme Court on 18 May 2023. Broad functional claims therefore require more extensive experimental data to enable a person skilled in the art to produce the claimed invention according to the full scope of the claim.

Support and enablement in Europe

The requirements in Europe are similarly very strict in relation to support and enablement in the antibody space. To satisfy the requirements for support under Art. 83, an application as filed must disclose the invention in a manner that is sufficiency clear and complete for it to be carried out by the person skilled in the art. With respect to antibodies, this assessment is occasionally complicated by a number of factors, given that this closely relates to the assessment for inventive step.

In Europe, there is a body of case law that discusses the issues of inventive step, as well as sufficiency of disclosure, since many of the processes surrounding the generation of antibodies are typically considered routine to try according to a person skilled in the art; whether this may concern methods of producing antibodies, generation of antibodies by mutagenesis, or even use of affinity assays.

Therefore, the challenges often faced by patent applicants in Europe, mostly concern obviousness of the antibody invention, provided that there is some disclosure on the antibody target, function and at least one antibody is exemplified in the specification as filed. This differs greatly from the US, where the examination criteria for support and enablement carry a greater weight for antibody inventions.

Should support and enablement objections be raised in these jurisdictions, it may be possible to address these issues by filing additional data. Although, the topic of post-filing data in the US, Europe and in Australia will be discussed in a separate supplementary article.

In the meantime, if you have any questions, please do not hesitate to contact our Life Sciences team. We will post our next article in this series shortly, which will discuss the criteria for inventive step for antibody inventions in Australia, Europe and in the US.