T 0411/19 - Plausibility for novelty and for priority

Key points

• Claim 1 is a second medical use claim directed to:  "A composition comprising at least one peptide that inhibits plasma kallikrein for the use in the treatment of ophthalmic disorders in a patient in need thereof, ..."
•  Patentee "had several lines of argument as to why document D2 did not disclose subject matter anticipating that of claim 1. They were i) that document D2 was not enabling for the medical treatment as defined in claim 1, because the experiments reported in document D2 did not constitute an actual treatment of any ophthalmic disorder, ..."
• "The appellant's first line of argument is based on the observation that "the experiments of D2 do not constitute an actual treatment of any ophthalmic disorder at all". This, however is not the right test for deciding whether a document discloses a medical use in such a way that it can be carried out by a person skilled in the art. Instead, the document should disclose the suitability of the product for the particular therapeutic application"
• "In view of [the experimental results in] document D2 [a PCT application establishes at least an initial plausibility that the compounds mentioned in claim 1 (of document D2), i.e inhibitors of the pathway set out in Fig. 6 of document D2, are suitable for achieving the therapeutic aim."
• " To counter this initial plausibility, evidence in the form of verifiable facts would be required to show that serious doubts exist about the claimed peptides' suitability for achieving the therapeutic effect. No such evidence has been put forward by [the patentee].
  
  
• "[The opponent] was of the view that subject-matter of this claim request is not entitled to the earliest priority date, 16 February 2006 because the application [P1] from which priority is claimed (EP 06360008) does not sufficiently disclose the suitability of the claimed compounds for the claimed therapeutic use"
• "According the established case law of the boards, a claimed second medical use meets the requirements of Article 83 EPC if the patent discloses the suitability of the product for the claimed therapeutic application, if this was not known to the skilled person at the relevant date []. This standard applies to priority documents equally, because the priority document must disclose the invention claimed in the subsequent application in such a way that it can be carried out by a person skilled in the art "
• " document P1 contains no experimental data or other evidence of any kind that goes beyond a mere allegation that the peptides defined in that document are indeed suitable for treatment of any of the ophthalmic disorders listed. That the peptides mentioned are suitable is not at all self-evident because it is the essence of the contribution to the art of the invention purportedly made in document P1. In the absence of such evidence, it cannot be concluded that document P1 provides even an initial plausibility that the claimed compounds are suitable for treating the disorders in question. "
• As a comment, it seems that a sentence stating verbatim "compound X is suitable for treating disease Y", is not a disclosure that compound X is suitable for treating disease Y in this context. Perhaps the term "disclose" is not entirely precise in the sense that what is required is something different from the gold standard test of G 2/10. See also T 2842/18. 
• "the passages cited by [the patentee] on page 6 [of P1] are not evidenc/e but mere allegations of suitability. In conclusion, document P1 does not disclose the invention of claim 1 in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art. The invention claimed in claim 1 of the main request is therefore not the "same invention" in the sense of Article 87(1) EPC* as the invention disclosed in document P1. Thus, the invention claimed in claim 1 of the main request cannot validly claim priority from document P1."
• * = Note, it might have been the same invention in the sense of G 2/98; at least this aspect of the disclosure in P1 is not disputed. 
• As a comment, the Board apparently saw no need to wait for G 2/21 even though one of the proposed answers in that referral is "no plausibility requirement at all" (in the context of inventive step, admittedly). 

EPO 

The link to the decision is provided after the jump, as well as (an extract of) the text of the decision.

https://www.epo.org/law-practice/case-law-appeals/recent/t190411eu1.html

Novelty (Article 54 EPC)

3. Document D2 (claim 1) discloses "a method of decreasing retinal vascular permeability in the eye of a subject, the method comprising administering to the subject a therapeutically effective amount of one or more of:

(i) an inhibitor of Carbonic Anhydrase-1 (CA-1) and/or Carbonic Anhydrase-2 (CA-2) signaling and optionally an inhibitor of Vascular Endothelial Growth Factor (VEGF) signalling;

(ii) an inhibitor of a kallikrein/kinin pathway; and/or

(iii) a Complement-1 Inhibitor (Cl-INH) agonist."

4. Document D2, in Fig. 6 also discloses a "hypothetical model of carbonic anhydrase-induced permeability, illustrating pathways that can be targeted using the methods disclosed herein." (page 15, lines 8 and 9). At page 16, lines 3 to 14, document D2 furthermore gives concrete examples of various suitable inhibitors, including a list of "Suitable kallikrein/kinin signalling inhibitors [that] can act at any point in the kallikrein/kinin pathway". There follows a list of inhibitors, including "Kunitz domain Kallikrein inhibitors, e.g., as described in U.S. Patent No. 5,780,265, e.g. DX-88 (Dyax, Cambridge, MA), described in Markland et al., Biochemistry 35:8058- 8067 (1996), and one or more of U.S. Patents Nos. 6,423,498, 6,333,402, 6,103,499, 6,071,723, 6,057,287, 6,010,880, 5,994,125, 5,837,500, 5,795,865, and 5,663,143". DX-88 is alleged (by appellant II) to be a peptide identical to SEQ ID NO: 23 of the patent in suit.

5. Appellant I had several lines of argument as to why document D2 did not disclose subject matter anticipating that of claim 1. They were

i) that document D2 was not enabling for the medical treatment as defined in claim 1, because the experiments reported in document D2 did not constitute an actual treatment of any ophthalmic disorder,

ii) that the skilled person needed to refer to other documents to identify the sequence of DX-88,

iii) that document D2 did not disclose the feature combination of claim 1.

6. The board is not persuaded by any of these arguments. The appellant's first line of argument is based on the observation that "the experiments of D2 do not constitute an actual treatment of any ophthalmic disorder at all". This, however is not the right test for deciding whether a document discloses a medical use in such a way that it can be carried out by a person skilled in the art. Instead, the document should disclose the suitability of the product for the particular therapeutic application (see Case Law of the Boards of Appeal of the European Patent Office, 10th edition, II.C.7.2). Document D2 establishes by way of experimental results, the link between carbonic anhydrase 1 (CA-1) and RVP and shows that co-injection of C1-INH, reduced CA-1 stimulated RVP by 92 % (see Example 2, page 40 first paragraph). In view of this, document D2 establishes at least an initial plausibility that the compounds mentioned in claim 1 (of document D2), i.e inhibitors of the pathway set out in Fig. 6 of document D2, are suitable for achieving the therapeutic aim. To counter this initial plausibility, evidence in the form of verifiable facts would be required to show that serious doubts exist about the claimed peptides' suitability for achieving the therapeutic effect. No such evidence has been put forward by appellant I.

7. The second line of argument, that the skilled person would not know that DX-88 represented a peptide having SEQ ID NO: 23, is not convincing. This is because it is evident from the cited passage on page 16 of document D2 that the compound was commercially available from Dyax, Cambridge, MA, under the name DX-88. The skilled person need not to be aware of the structure of the compound referred to as this is an inherent feature of the named molecule. That DX-88 is a peptide identical to SEQ ID NO: 23 of the patent under appeal has been demonstrated, inter alia in patent document D13 with a filing date 7 February 2003 (column 12, lines 19-20, column 62, Table 2). There is no reason to assume that the structure of DX-88 was changed between this date and the filing date of the patent and such change is not probable. The board also sees no grounds for the allegation that, in spite of the clear indication on page 16, lines 3 and 12 that DX-88 is a kallikrein/kinin signalling inhibitor, DX-88 is in fact a PRCP inhibitor.

8. The third argument cannot convince either. Although in claim 1, document D2 discloses three separate categories of functionally defined inhibitors used in a method of decreasing retinal vascular permeability in the eye of a subject, the skilled person does not need to resort to any of these categories to arrive at the claimed subject-matter. Instead, a list of active agents is given starting on page 15. The skilled person can select any of these compounds to achieve the therapeutic aim. This compound will then inherently fall within one of the categories without a further selection. Compound DX-88 (present SEQ ID NO: 23) is mentioned in the category of inhibitors of the kallikrein pathway (see page 16, first full paragraph). The ability to inhibit kallikrein is therefore an inherent attribute of DX-88. Thus, only a selection from a single list of inhibitors needs to be made to arrive at subject-matter falling within the scope of claim 1.

9. In view of these considerations, the subject-matter of claim 1 of the main and auxiliary request 1 lacks novelty.

Auxiliary request 2 (filed during the oral proceedings)

10. Claim 1 of auxiliary request 2 differs from claim 1 of the main request in that the condition to be treated is limited to macular oedema and retinal vein occlusion.

Admission (Article 13(2) RPBA)

11. Auxiliary claim request 2 was filed at the hearing before the board. It was admitted into the appeal proceedings at the discretion of the board. However, in view of the board's decision on inventive step, the reasons for this need not be given here.

Priority (Article 87 EPC)

12. Appellant II was of the view that subject-matter of this claim request is not entitled to the earliest priority date, 16 February 2006 because the application from which priority is claimed (EP 06360008) does not sufficiently disclose the suitability of the claimed compounds for the claimed therapeutic use, i.e. for the treatment of macular oedema or retinal vein occlusion.

13. According the established case law of the boards, a claimed second medical use meets the requirements of Article 83 EPC if the patent discloses the suitability of the product for the claimed therapeutic application, if this was not known to the skilled person at the relevant date (see Case Law of the Boards of Appeal of the European Patent Office, 10th edition, II.C.7.2). This standard applies to priority documents equally, because the priority document must disclose the invention claimed in the subsequent application in such a way that it can be carried out by a person skilled in the art (Id. II.D.3.1.6).

14. The question to be answered in determining if the subject-matter of claim 1 can validly claim priority from P1 is therefore whether or not said priority document discloses that the claimed compounds are suitable for treating macular oedema and retinal vein occlusion. It was not in dispute that document P1 discloses Kunitz domain peptides according to the general formula of claim 1 of the patent in suit and states that these are useful in the treatment of ophthalmic disorders in humans and animals. Macular oedema and retinal vein occlusion are both mentioned in lists of treatable ophthalmic disorders, for instance in the paragraph bridging pages 14 and 15. There is therefore a literal disclosure of the subject-matter of claim 1.

15. However, document P1 contains no experimental data or other evidence of any kind that goes beyond a mere allegation that the peptides defined in that document are indeed suitable for treatment of any of the ophthalmic disorders listed. That the peptides mentioned are suitable is not at all self-evident because it is the essence of the contribution to the art of the invention purportedly made in document P1. In the absence of such evidence, it cannot be concluded that document P1 provides even an initial plausibility that the claimed compounds are suitable for treating the disorders in question. The passages on page 4, referred to by appellant I as providing a link between particular plasma kallikrein inhibitors and the ophthalmic disorders are no more than a summary of the background knowledge in the art on proteases, including kallikreins and their inhibitors. These passages do not at all constitute evidence that peptides defined in document P1 are suitable for treatment of any ophthalmic disorder by inhibiting plasma kallikrein. Similarly, the passages cited by appellant I on page 6 are not evidence but mere allegations of suitability. In conclusion, document P1 does not disclose the invention of claim 1 in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art.The invention claimed in claim 1 of the main request is therefore not the "same invention" in the sense of Article 87(1) EPC as the invention disclosed in document P1. Thus, the invention claimed in claim 1 of the main request cannot validly claim priority from document P1.

16. In view of the above decision on priority, document D2. which was published on 31 August 2006 is prior art under Article 54(2) EPC.