T 0296/87 - Enantiomers - #99

Rank: 99
Number of citations: 55

This decision, ranking #99 on the list of the EPO's most-cited Board of Appeal decisions  deals, i.a., with the question whether an opponent, who filed restricted claims in the course of opposition proceedings, can subsequently file claims broader than the previous ones (but still within the limits of Art. 123(3), of course).

The decision also deals with the question of novelty of specific configurations of chemical compounds (e.g. enantiomers) over a more general disclosure of the chemical structure (e.g., racemates).

1. Broadening of claims during opposition

Regarding the issue of broadening the scope of the claims relative to a version of the claims previously filed in opposition, the Board in T 296/87 held:

"2.2 Moreover a Board of Appeal had already decided (T 123/85 of 23 February 1988, OJ EPO 1989, 336) that the EPC made no provision for a patentee to surrender his patent in opposition proceedings, which meant that (even had there been an express declaration of surrender, which was not the case) he could not surrender his patent either wholly or in part. He could only request that it be amended and, in principle, could withdraw or amend such a request at any time provided no abuse of procedural law was involved (cf. points 3.1.1 and 3.1.2 of the decision cited). In the present case there is nothing to indicate any such abuse; in fact the complexity of the subject-matter makes it understandable that the appellants should have been most unsure as to what form of limitation the EPO would accept for establishing novelty."

A later decision, T 368/98, uses these principles in the context of a broadening of claims relative to claims refused by the opposition division and cites T 296/87 as follows:

"2.3. Even if the amended claim were to be seen as broader than the claim refused by the opposition division, the board finds the amendment admissible under the case law, which allows broadening on appeal, unless it would constitute abuse of proceedings (see eg. decisions T 89/85 of 7 December 1987 and T 296/87, OJ EPO 1990, 195)."

In other words, by filing restricted claims in opposition division, the patentee does not surrender the scope no longer claimed by the restricted claims. He can re-claim that subject matter later, in a further attempt to formulate allowable claims (within the limits of Art. 123(3), of course)

 

2. Novelty of specific configurations of chemical compounds

The Board also had to decide on the issue of when a chemical substance is disclosed by the prior art. The Board referred to T 181/82 ("Spiro compounds"), where it was held that the disclosure "C1-C4 alkyl" does not individually disclose all members (including isomers, namely: methyl (C1), ethyl (C2), n- and iso- propyl (each C3), and n-, sec.-, iso- and tert.-butyl (each C4)).

By analogy, the Board found that disclosure of racemates in the prior art did not take away novelty of the claims, which related to specific enantiomers contained in those racemates:

6.2 The Board believes this principle applies in the present case to the extent that, judging by expert interpretations of the structural formulae and scientific designations to be found in the prior art, the latter describes only racemates. Given the asymmetrical carbon atom in the formula, the substances in question can indeed occur in many conceivable configurations (D- and L-enantiomers); that alone does not mean, however, that these configurations are disclosed in individualised form. The novelty of the D- and L-enantiomers is therefore not destroyed by the description of the racemates.

Novelty of the claimed enantiomers was therefore not destroyed in the specific case.

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Headnote:

A chemical substance is held to be new if it differs from a known substance in a reliable parameter. The configuration is such a parameter. If the prior art describes specific racemates in more detail by reference to their structural formulae, that alone does not disclose their specific configurations (here D- enantiomers); see points 6 and 7 of the Reasons (in conjunction with T 12/81 "Diastereomers", T 181/82 "Spiro compounds" and T 7/86 "Xanthines" in OJ EPO 1982, 296; 1984, 401; and 1988, 381 respectively).

The complete text of the decision can be accessed here.