The decision in G 1/15 issued earlier this year (reported by me here), confirming that partial priority was allowable for claims that encompassed an earlier priority application. This finally and emphatically killed off the idea of poisonous priority. For the application in question that led to the Enlarged Board referral, however, this was not the end of the story.
The application, EP98203458.9, in the name of Infineum UK Ltd., was granted in 2010 and opposed by Clariant Produkte (Deutschland) GmbH. One of the grounds of opposition, which eventually became the sole remaining point on appeal, was that granted claim 1 was not novel over the patent's own priority document, as a result of it not being entitled to priority. This resulted in a referral to the Enlarged Board, which decided: "Under the EPC, entitlement to partial priority may not be refused for a claim encompassing alternative subject-matter by virtue of one or more expressions or otherwise (generic "OR"-claim) provided that said alternative subject-matter has been disclosed for the first time, directly, unambiguously and in an enabling manner in the priority document. No other substantive conditions or limitations apply in this respect". The implication of this was that claim 1 did have a partial priority right to the earlier narrower disclosure, which did not therefore become novelty destroying. The Enlarged Board then referred the matter back to the lower Board of Appeal to decide on the point in question.
The Board of Appeal have now issued their further decision in T 557/13. This confirms that the only novelty objection was in relation to whether the granted claim 1 was entitled to partial priority. In light of the decision in G 1/15 the priority document could not be novelty destroying, since the effective filing dates for that subject matter were the same. The Board of Appeal noted that inventive step objections that had been raised by the opponent were not dealt with under appeal, and therefore decided to remit the case to the Opposition Division for further prosecution.
The case, which has now been going for just over six years, will now have to go on a bit longer still before it can be finally settled (even though the patent finally expired in June 2015). I wonder how much longer the case can be drawn out, and if it will go yet again to the Boards of Appeal after the Opposition Division decide on the remaining inventive step points.