The first round of the Australian CRISPR patent dispute has concluded, with the patent office ruling that claims directed to platform CRISPR technologies lack novelty and an inventive step.

The dispute concerned ToolGen Incorporated’s patent application for compositions and methods comprising Type II CRISPR systems.  To appreciate the potential value of ToolGen’s application, it is worth reciting claim 1:

A composition comprising a Type II Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas system for use in introducing a site-specific, double stranded break at a target nucleic acid sequence in a eukaryotic cell, said CRISPR/Cas system comprising (i) a nucleic acid encoding a Cas9 polypeptide comprising a nuclear localization sequence, and (ii) a nucleic acid encoding a guide RNA that hybridizes to a target nucleic acid, wherein the guide RNA is a chimeric guide RNA comprising a CRISPR RNA (crRNA) portion fused to a trans activating crRNA (tracrRNA) portion.

In Australia, the term “for use” does not limit a claim to any particular use, and as such, claim 1 defines a composition per se, provided that composition is suitable for the specified use.  ToolGen’s application also includes method claims which broadly define the use of the Type II CRISPR/Cas system to introduce double-stranded breaks in eukaryotic cells.

The application was opposed by an apparent “straw man” – in this case, an Australian solicitor – on several grounds including that the claims lacked clarity, that they were not sufficiently enabled or supported by the disclosure of the specification and that they lacked novelty and an inventive step.

Crucial to the issue of novelty and inventive step, was the question of priority date.  ToolGen’s application claimed priority from three US provisional applications, and pursuant to the earliest priority dates being found invalid, three landmark publications (Cong et al. (2013) Science 339: 819-812; Mali et al.  (2013) Science 339: 823-825; and Wang et al. (2013) Cell153: 910-918) would become relevant prior art.

In construing the claims, the Delegate considered the term “a nucleic acid encoding a guide RNA” to define DNA that encodes a guide RNA but not the guide RNA itself.  This construction proved critical as the earliest priority document failed to describe DNA encoding a guide RNA.  Rather, the document described only in vitro transcribed guide RNA.  On that basis, the Delegate ruled that the claims were not entitled to their earliest priority date, and consequently, found that all but two of the claims lacked novelty or an inventive step, with one claim being found to lack clarity.

The door is open for ToolGen to amend its claims and overcome the prior art.  The Delegate’s decision may also be appealed to the Federal Court.

Grant Fisher v ToolGen Incorporated [2018] APO 65