New ILPTO Commissioner further clarifies the patentability thresholds of polymorphs

In a recent opposition decision, the ILPTO rejected GSK’s patent applications directed to a specific crystalline form of the JAK inhibitor momelotinib dihydrochloride. The decision is particularly interesting because it is the first substantive decision of the recently appointed Commissioner on patentability of polymorphs and further clarifies the standards applied by the ILPTO.

The Commissioner correctly rejected Opposer’s lack of novelty arguments holding that it failed to establish that the prior art processes necessarily and invariably produce the claimed polymorph. The Commissioner however held that the claimed polymorph was a predictable result of routine polymorph screening of a known hydrochloride salt using standard methods. In rejecting the applications on grounds of lack of inventive step, the Commissioner emphasized that Applicant conceded that the crystallization of the claimed polymorph did not involve any particular technical difficulties and that the advantages which Applicant claimed are exhibited by the polymorph (e.g., improved stability) were merely the ‘target advantages’ of any routine polymorph screening. In addition, the Commissioner rejected the applications because the precursor polymorph used to make the claimed crystalline form via recrystallization was not adequately enabled in the application or in the prior art.

Unlike some previous ILPTO polymorph decisions, the Commissioner correctly applied the novelty tests by unequivocally holding that inherent anticipation will only be found if reproducing the prior art necessarily and invariably results in subject matter falling within the claims. With respect to inventive step, the Commissioner reaffirmed previous ILPTO case law, under which inventive step will be established if the polymorph screening and selection process involved technical difficulties or if the advantages of the novel polymorph are significant, unexpected and not of a type routinely identified in polymorph screening. As this is also clearly indicated in the ILPTO Working Guidelines, it is somewhat surprising that Applicant merely pursued standard arguments on the general lack of predictability of polymorphs which the ILPTO has consistently found insufficient to establish inventive step for quite some time.

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