T 1041/23 (Dapagliflozin formulations / ASTRAZENECA) 10-04-2025

1. Procedural violation

1.1 According to the appellant, the proceedings are affected by a violation of the right to be heard because the appealed decision is based on grounds on which they had no opportunity to present their comments, namely the critical reasoning (given at §2.2.2.8 of the decision) about how the skilled person would have been able to isolate and analyse the crystalline 1:1:1 dapagliflozin (S)-PG monohydrate (1:1:1-DSPGM) from the clinical trial tablets.

The Board agrees for the following reasons.

1.2 The relevant parts of the proceedings before the opposition division may be summarised as follows:

The objection of lack of novelty over the clinical trial reported in D1 was initially raised by opponent 1 in their notice of opposition (see §5). Concerning the possibility to analyse the medication administered in this clinical trial, opponent 1 mentioned various analytical techniques, such as HPLC/MS and XRPD, that would allow the determination of the active ingredient as containing propylene glycol and the fact that it was in crystalline form, i.e. in the form of the propylene glycol solvate (see §5.3).

With their reply dated 25 June 2021 (see page 12-13), the patent proprietor countered that this prior use was not public, and in particular that no evidence had been adduced that patent proprietor lost control of the medication during clinical trials.

In the preliminary opinion dated 6 October 2021 (see §4.2), the opposition division briefly expressed the view that the skilled person was in the position to analyse the medication and discover all technical features of claim 1, and that the sole question was whether the prior use was public.

In their further letter dated 19 May 2022 (see §2.2), the patent proprietor emphasised that, even assuming that the study medication became public during the clinical trial, given the presence of the additional excipients, a skilled person attempting to analyse the study medication used in the clinical trial would not have been able to conclusively discover that dapagliflozin was present in the claimed solvate form, namely dapagliflozin . water . S-propylene glycol in a 1:1:1 stoichiometry.

In section §2.2.1.7, the appealed decision addresses the question of whether all technical features of claim 1 could be retrieved by analysing the study medication. The opposition division reasons that the skilled person would be able to separate the excipients from the insoluble dapagliflozin propylene glycol hydrate by placing the tablet of the clinical study in an aqueous physiological medium. The decision then mentions various techniques for the analysis of the crystal, citing D10, D15 and D11, and concludes that these would allow the determination of the active ingredient being a crystal containing dapagliflozin, propylene glycol and water in the proportions 1:1:1.

Likewise, in section §2.2.2.8, the opposition division reasons that the dapagliflozin propylene glycol hydrate is not soluble in a physiological aqueous medium, whereas the tablet dissolves in aqueous medium, thus leaving the crystal in solid form. Once isolated, the crystal can be fully analysed in order to ascertain its structure, using any of the methods described in D10.

1.3 Thus, the issue of whether the technical features of claim 1 could be determined by analysing the study medication was the topic of debate from the beginning of the opposition proceedings.

However, in reply to the appellant's objection that the analysis of the medication containing excipients would not allow to identify the claimed solvate form therein, the decision proposes for the first time a method for isolating the solvate from the medication by dissolution in a physiological aqueous medium, followed by analysis of the remaining insoluble crystal. This specific part of the reasoning had not been discussed at any point during the preceding opposition proceedings.

In this respect, the respondents emphasised the lack of details in the minutes of the oral proceedings before the opposition division, and submitted that, while they could not remember exactly, both the issues of separating the excipients from the crystalline material and of analysing the crystalline material had been a topic of discussion during these oral proceedings. However, the respondents do not dispute that the specific method of isolating the solvate from the tablet by dissolution in a physiological medium so as to analyse the crystal was never mentioned during the oral proceedings. There is not indication in the minutes of any discussion on this point either.

1.4 Under Article 113(1) EPC, the decisions of the EPO may only be based on grounds or evidence on which the parties concerned have had an opportunity to present their comments. The grounds or evidence under Article 113(1) EPC are to be understood as meaning the essential legal and factual reasoning on which the decision is based (see the Case Law of the Boards of Appeal, 10**(th) edition, 2022, hereinafter "Case Law", III.B.2.3.2).

The factual allegations regarding the solubility properties of the solvate according to claim 1, and the specific isolation method based thereon proposed by the opposition division, are an essential part of the decision, in the sense that the decision does not suggest any means of ascertaining by analysis the presence of the claimed solvate in the medication other than by firstly resorting to this isolation method. Contrary to respondent 4's view (see their reply dated 8 December 2023, pages 12-13), the appealed decision does not indicate any means of analysing the whole tablets for the presence of the claimed solvate without separating its components, i.e. neither explicitly nor implicitly by citing D10 (paragraphs [0177]-[0195]), D15 (pages 41-42) or D11 (example 7 on pages 43-44), as these documents pertain to the analysis of e.g. isolated solvates as such but not as part of a complete medication including excipients.

1.5 The Board concludes that the first-instance proceedings are affected by a substantial procedural violation.

1.6 The respondents point out the opposition division's preliminary view that "The skilled person is in the position to analyse a dosage form like the Forxiga product and to discover all technical features of present claim 1 (G 1 /92)" (see the annex to the summons dated 6 October 2021, §4.2). According to the respondents, the appellant did not react early enough to this position, i.e. the burden of proving that the tablet could not be analysed or its components separated rested with the appellant. They further submit that the presence of the solvate in the tablet could otherwise be ascertained using well-known analysis techniques, even without destroying the tablet. They finally take the view that, in light of the pending referral G 1/23, the possibility to analyse the product might not be a requirement for it to be accessible to the public.

However, the question under Article 113(1) EPC is whether the appellant had an opportunity to present their comments on the factual reasoning used in the decision. The appealed decision reasons that, following G 1/92, the features of claim 1 characterising the formulation are available to the public if they could be retrieved by analysing the tablet from the clinical study, and concludes that this was possible by isolating the solvate from the medication by dissolution in a physiological aqueous medium, followed by analysis of the remaining insoluble crystal. Whether the same finding that the composition of the tablet was prior art could alternatively have been justified by reasonings others than the one used in the decision has no bearing on the issue of right to be heard. It is thus not necessary, for that purpose of Article 113(1) EPC, to assess whether the burden of proving that the tablet could not be analysed rested with the appellant, or whether the tablet could be analysed as such without prior separation, because the decision is not based on such aspects. It is for the same reasons not necessary to speculate on the answers to be given by the Enlarged Board of Appeal in the current referral G 1/23, and whether the possibility to analyse the features of the tablet could become irrelevant to their being state of the art, because the assumption that analysability is a requirement is also an essential part of the reasoning in the appealed decision.

1.7 Accordingly, the appealed decision does not meet the requirements of Article 113(1) EPC and must be set aside for this reason. Respondent 3's unspecific considerations of procedural economy cannot lead to a different conclusion because they cannot take precedence over the fundamental right to be heard enshrined in Article 113(1) EPC.

2. Remittal and reimbursement of the appeal fee

Under Article 11 RPBA, the Board shall not remit a case to the department whose decision was appealed for further prosecution, unless special reasons present themselves for doing so. As a rule, fundamental deficiencies which are apparent in the proceedings before that department constitute such special reasons.

In the case at hand, the above substantial procedural violation is a fundamental deficiency in the sense of Article 11 RPBA. The Board therefore decides to remit the case to the opposition division for further prosecution.

As a further consequence of this substantial procedural violation, a reimbursement of the appeal fee is equitable under Rule 103(1)(a) EPC.

3. Admission of documents D53-D56, D60 and D61

Respondent 5 requested at the end of the oral proceedings that the Board decide on the admission of documents D53-D56, D60 and D61 in the appeal proceedings, that is before remittal to the opposition division.

The Board could in theory, under Article 111(1) EPC, exercise the opposition division's discretionary power regarding admittance of these documents. This would however not be appropriate for the following reasons. As explained above, in view of the substantial procedural violation, the Board can decide on the appeal by setting aside the appealed decision and remitting the case. This entails that the opposition division is to further prosecute the case and assess, if need be, whether any late filed evidence is to be admitted. A decision by the Board on the admittance of D53-D56, D60 and D61 is not only unnecessary to decide on the appeal, but would even be inappropriate as it would pre-empt the opposition division's overall examination.

Accordingly, appellant 5's request was rejected.

4. Apportionment of costs

4.1 The appellant's request for an apportionment of costs was made in the following context:

In the communication under Article 15(1) RPBA, the Board had already expressed the preliminary view that the first-instance proceedings were characterised by a substantial procedural violation justifying both a remittal of the case to the opposition division for further prosecution and a reimbursement of the appeal fee. In the same communication, the Board had invited the parties to clarify their requests for oral proceedings before the Board in this event.

In reply, the appellant agreed to the remittal, but respondents 3, 4 and 5 maintained their requests for oral proceedings in case the appeal would not be dismissed.

The appellant questioned the need for oral proceedings in a letter dated 14 March 2025. Then, at the end of the oral proceedings before the Board, the appellant submitted a request for a different apportionment of costs, with their preparation, travel and accommodation costs to be divided between respondents 3, 4 and 5. The appellant justified their request by the conduct of respondents 3, 4 and 5, who had persisted in their request for oral proceedings despite knowing of the violation of Article 113(1) EPC.

4.2 Under Article 104(1) EPC, each party to the opposition proceedings shall bear the costs it has incurred, unless the Opposition Division, for reasons of equity, orders, in accordance with the Implementing Regulations, a different apportionment of costs. In opposition appeal proceedings, the same rule applies: in application of Article 16(1) RPBA, the Board may on request order a party to pay some or all of another party's costs, but this is subject to Article 104(1) EPC. Thus, departing from the general principle that each party bear its own costs requires special circumstances making such a departure equitable. The equity criteria has generally been interpreted by the Boards such that apportionment of costs is justified if the conduct of one party is not in keeping with the care required, that is if costs arise from culpable actions of an irresponsible or even malicious nature (see Case Law, III.R.2).

No such special circumstances are apparent in the present case. The fact that respondents 3, 4 and 5 upheld their requests for oral proceedings can neither be regarded as abusive nor in breach of their duty of care. Their behaviour does not go beyond a legitimate defence of their position and argumentation that no substantial procedural violation occurred, and a normal exercise of their absolute right to oral proceedings under the circumstances. While the Board expressed an opinion in the Article 15(1) RPBA communication which was contrary to the position of the respondents, this opinion was merely a preliminary one, and there was nothing abusive in the respondents upholding their position and presenting their arguments at the oral proceedings. The appellant's speculation that the respondents knew of the violation of Article 113(1) EPC is in this respect completely irrelevant: the respondents certainly knew of the facts of the case, i.e. attended the oral proceedings and were notified the decision, but they were nonetheless entirely entitled to present legal arguments to the effect that these facts did not amount to a violation of the right to be heard. Lastly, none of the typical situations recited in Article 16(1) RPBA were relied on by the appellant or apply here, namely (a) amendment to a party's appeal case pursuant to Article 13; (b) extension of a period; (c) acts or omissions prejudicing the timely and efficient conduct of oral proceedings; (d) failure to comply with a direction of the Board; (e) abuse of procedure.

4.3 Accordingly, the Board rejected the appellant's request for a different apportionment of costs.