T 2643/16 - Sofosbuvir

Key points

• This decision is about a blockbuster medicament and involves plausibility, transfer of priority, and diastereomers. What's not to like about it? Perhaps that the Board stays the procedure until the Enlarged Board decides on the pending referrals.
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• "The objection [under Art. 123(2)] was primarily raised against [dependent] claims 2 and 3, which single out the diastereomers of the compound in claim 1 having (S)- or (R)-configuration at the phosphorous atom."
• "The basis for claims 2 and 3 in the application as filed given by the appellant-patent proprietor []  is the following: (i) compound IX-25-2 (page 254) in light of the explanation of Tables II-1 to XXXII-50 given on page 99, line 17 to page 100, line 5 and the passage on page 20, lines 8 to 16; (ii) Example 25 (page 683) [!] in light of the passage on page 20, lines 8 to 16"
• The PCT application is 751 pages. The file is slightly above 19k pages now.
• "Regarding (i), compound IX-25-2 is disclosed in Table IX-25. It has the chemical structure of the compounds of claims 2 and 3 but does not specify the configuration of two chiral centres, namely the phosphorous atom and the chiral carbon atom of the amino acid moiety."
• "As to the configuration of the phosphorous atom, the passage on page 20, lines 8 to 12 discloses that the claimed compounds "are racemic because of the chirality at phosphorous", the phosphorous atom being "R" or "S", and that "the use of the racemate and/or the resolved enantiomers" is contemplated."
• "The board agrees with the appellant-opponents and respondent-opponents that these general statements on pages 20, 99 and 100 are merely a conceptual description of the diastereomers encompassed by structures II to XXXII owing to the chirality at the phosphorous atom. The reference to the generic structures rather than the specific compounds renders it ambiguous whether the general statements apply to each table and compound disclosed below structures II to XXXII. But more importantly, the general description of the chirality at the phosphorous atom does not constitute a direct and unambiguous individualisation of each of the two diastereomers of each of the thousands of compounds disclosed in Tables II-1 to XXXII-50 having the preferred (S)-configuration at the amino acid moiety."
• The claims are found to lack basis in the application as filed.
  
  
• Turning to AR-1, being the AR held allowable by the OD, claims 2 and 3 are cancelled.
• Some but not all of the opponents appealed. " Therefore, the principle of prohibition of reformatio in peius precludes the consideration by the board of any objection against this request raised exclusively by the parties as of right (respondent-opponents). "
• By way of comment, see T 0920/20: "The Board cannot derive any restriction from Article 12(4) RPBA that each party may only refer to those matters of the preliminary proceedings in the appeal which it itself has introduced there in a permissible manner. It therefore seems legitimate for the appellant to also refer to lines of attack introduced by other opponents in the opposition proceedings." 
• Reformatio in peius deals with subject-matter, not with individual attacks or objections.
• However, perhaps a principle of estoppel can be identified.  
  
  
• "It was a matter of dispute between the parties whether the applicant, when filing the application on which the patent is based, was entitled to claim priority from the earlier applications D1 and D2 and, in this context, whether the applicant was the successor in title of the applicants that filed priority applications D1 and D2."
• "The outcome of referral cases G 1/22 and G 2/22 is therefore relevant for the board's decision on the validity of the priorities claimed in the case in hand. For this reason, in line with the appellant-patent proprietor's request and in the absence of any objection against a possible stay of the proceedings, the board decided not to take a decision on the issue of entitlement to priority but to await the outcome of these referral cases."
• "The appellant-opponents cited documents D33, D35, D12, D10, D9, D8, D7, D6 and D4 as starting points for the assessment of inventive step."
• "The patent (paragraph [0001]) is concerned with the preparation of nucleoside prodrugs that inhibit [hepatitis C virus (HCV)] replication and their use for treating HCV infection."
• "The appellant-patent proprietor argued that this starting point was not the closest prior art and that its choice involved hindsight. However, in accordance with the established case law of the boards, a conclusion that the subject-matter claimed is inventive can only be reached after assessing this requirement starting from all the possible pieces of closest prior art. Therefore, the appellant cannot argue against assessing inventive step starting from [compound] RO2433 [in D33]."
• "The compound of claim 1 differs from RO2433 by its phosphoramidate moiety."
• "According to document D10, cited in paragraph [0018] of the patent in suit, RO2433 is not active against HCV []. In contrast, the patent shows in Example 82 (Table, Example 25) that the compound of claim 1 inhibits in-cell HCV replication at sub-micromolar concentrations"
• "Based on this technical effect, the objective technical problem is the provision of an effective compound for the treatment of HCV infection."
• "Starting from compound RO2433 in D33 and faced with the problem of finding an effective compound for treating HCV infection, the skilled person had no motivation to turn to D7 because they did not know that RO2433 was inactive against HCV. The skilled person was even less likely to know that the reasons for the lack of activity of RO2433 were those intended to be overcome by the authors of D7, namely poor membrane permeation and/or a poor phosphorylation rate by cell enzymes. Therefore, the combination of D33 with D7 is based on hindsight."
• The Board then als considers  D12 as the closest prior art, as well as D10, and D7 (there were multiple opponents-appellants). None of the attacks is successful.
• " For the above reasons, the board concludes that the compound of claim 1 is inventive over the cited prior art available to the public before the earliest priority date."
• "The issue of whether post-published evidence may be taken into account may become relevant for assessing the inventive-step objections involving [remaining documents] D6, D8 and D9. Therefore, the outcome of the presently pending referral case G 2/21 on plausibility may also be relevant."
  
  "The case has come to a point at which a stay of proceedings is considered required. At the date of the oral proceedings, no information existed on when a decision would be handed down in the three pending referral cases G 2/21, G 1/22 and G 2/22. This, together with the fact that one of the five board members will retire on 1 March 2023, led the board to decide, as announced at the oral proceedings, to issue an interlocutory decision on the issues for which the parties could provide their comments at the oral proceedings and for which the board closed the debate."
   

EPO 

The link to the decision is provided after the jump

https://www.epo.org/law-practice/case-law-appeals/recent/t162643eu1.html