As I reported in February last year, Gilead's European patent EP2203462B1 to sofosbuvir (Sovaldi) was opposed by various organisations, the first of which was Médecins du Monde (MdM). Their main reason for opposing the patent seemed to be that Gilead was charging a high price for the drug, which is effective for treating Hepatitis C. The opposition has recently concluded, following oral proceedings earlier this month. A press release issued on October 5th indicated that MdM's opposition was partially successful, and that "the quality of the patent was weak". Details of how exactly the patent fared as a result of the opposition were, however, missing, except for a mention that "the patent extended beyond the content of the patent application as filed" (suggesting an Article 123(2) issue). Another report from IP Watch did not provide much in the way of further illumination, and as yet there has been no word from Gilead or the EPO on the outcome.
The decision and minutes of the oral proceedings have not yet appeared on the EP register for the case, and are unlikely to do so for some time. It can, however, be inferred from what has already been said, and in particular a document that has appeared on the register, what actually happened.
In their preliminary opinion, issued on January 28, 2016, the opposition division indicated that claim 1, corresponding to the racemate (shown here), had been specifically disclosed in the application as filed. Claims 2 and 3, however, which were directed to the enantiomers (or diastereomers - see the comment below), did not appear to be disclosed. Whether the disclosure was sufficient to disclose the enantiomers was something that was due to be discussed at the oral proceedings.
Gilead filed a large number of auxiliary requests, the first of which had a set of claims that had been amended to define the enantiomers instead in terms of the slow and fast eluting isomers obtainable by a specific method that was disclosed in the application. The clue that this succeeded at oral proceedings is this document, issued shorty after the proceedings, that contains amendments made to the summary of the invention, and indicating that this corresponds to the first auxiliary request. This shows that claims 2 and 3 have been removed from the application, clearly indicating that claim 1 survived, but that the specific claims to the enantiomers did not.
As a result, the patent seems to me to have survived pretty well, and not really limited in any substantial way. It will, of course, be irritating to Gilead that the specific claims to the enantiomers have gone, but the patent as amended would still protect the drug. Reports (such as this one, for example) that suggest generics may be able to enter the market sooner than expected, therefore seem to be a bit wide of the mark.
UPDATE 3/11/16: The grounds for the decision have now appeared on the EP register. As expected, claim 1 to the racemate stands, and the claims to the enantiomers/diastereomers have gone.