Inherency is not relevant to the novelty of a "purpose-limited product claim" filed in accordance with Article 54(5) EPC.

The EPO's Technical Board of Appeal 3.3.09 in T0694/16 has clarified that claims to purposively selected patients for treatment with a known drug is novel over the prior art treatment of a broader and/or overlapping patient group with the same drug.

If there is a functional relationship between one or more biomarkers and responsiveness to treatment with a drug, and the claim defines the drug for use in the treatment of a patient defined by said biomarkers, then the presence of this functional relationship confirms that the purposive selection of the patients is an essential technical feature qualifying the claim(s), and this must be taken into account when assessing novelty.

The rationale for ruling that inherency is not relevant to the novelty of a "purpose-limited product claim" filed in accordance with Article 54(5) EPC is neatly summed up in points 5.12-5.14 of T0694/16:

"5.12. When deciding on the novelty of claims directed to a new use of a known compound, the Enlarged Board of Appeal has already considered that "...a line must be drawn between what is in fact made available and what remains hidden or otherwise has not been made available...". Thus, the relevant issue is what has been made available, and not "...what may have been inherent in what was made available..." (G 2/88, points 10-10.1).

5.13 The board in the present composition is of the opinion that this principle applies also to claims drafted under Article 54(5) EPC. The relevance of G 2/88 to claims directed to the treatment of new patient groups has already been endorsed in T1118/12 (point 7). It is also supported by the statement in G2/88 that "...the question of "inherency" does not arise under Article 54 EPC" (i.e. in relation to all aspects of novelty).

5.14 For this reason, the issue of whether patients displaying the markers of claim 1 were present among a population of previously treated patients and were already "inevitably" or "inherently" treated is irrelevant for assessing novelty in the present case..."

This decision deviates from the ruling in T233/96, in which it was held:

"If the use of a compound was known in the treatment or diagnosis of a disease of a particular group of subjects, the treatment or diagnosis of the same disease with the same compound could nevertheless represent a novel therapeutic or diagnostic application, provided that it was carried out on a new group of subjects which is distinguished from the former by its physiological or pathological status (T0019/86, T0893/90).

This does not apply, however if the group chosen overlaps with the group previously treated...". (emphasis added) (T233/96, Headnote).

How did the board in T0694/16 justify their departure from T233/96?

The ruling in T233/96 that the claimed group must not overlap with the group previously treated was based on interpretation of two prior cases (T19/86 and T893/90). The board in T0694/16 stated that the interpretation of T19/86 and T893/90 given in T233/96 has no basis in the relevant parts of those decisions (points 5-8 of T19/86 and points 4.2 -4.6 of T 893/90). (T0694/16, point 5.19).

"5.20. The conclusions drawn in T233/96 thus cannot be applied to the present case, where the treated patients are identified by clearly testable criteria. Accordingly, novelty may not be denied on the ground that the claimed patient group is embedded and necessarily overlaps with a larger population of previously treated patients and the first condition in T233/96 is not satisfied." (T0694/16, point 5.20).

Thus, with regard to the novelty of a known drug for use in treating a purposively selected group of patients, the crucial issue is whether this purposive treatment has been made available to the public within the meaning of Article 54(2) EPC.

This decision provides clarity for those working on personalised medicines, reaffirming the EPO's practice of allowing protection for a diverse range of subject matter in this area.

Even if a drug has been used to treat a general group of patients, an individual that determines how to identify the patients that best respond to the drug could secure a European patent covering the drug's use in the treatment of such purposively selected patients.

The EPO's relatively permissive approach in this area contrasts dramatically with the USPTO's extremely restrictive position on personalised medicine inventions, especially for section101 patent eligibility, in view of the Mayo v. Prometheus Supreme Court decision (566 U.S. 66, 132 S. Ct 1289, 2012).

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