Merck & Co's dispute with Johnson & Johnson over the marketing rights to the rheumatoid arthritis and Crohn’s disease blockbuster Remicade and newer arthritis treatment Simponi is unlikely to be settled before year-end, as had been expected.

The legal spat began in May last year when J&J initiated an arbitration process claiming that Merck's takeover of Schering-Plough constituted “a change of control” that would permit the ending of its marketing agreements with the latter regarding Remicade (infliximab) and Simponi (golimumab). Merck argues that the partnership should remain intact because it structured the deal as a reverse merger, allowing S-P to remain as a surviving entity.

Merck now says that the hearing has now concluded, but under an agreement with the arbitration panel, the companies will file post-hearing briefs. They will then present arguments to the panel at the end of December so it "anticipates a decision in 2011".

Merck had previously stated it expected a decision some 20 days from the conclusion of the hearing, so observers thought the case would be settled at the beginning of November.

There is a lot of cash up for grabs, especially with Remicade, which had worldwide sales of $5.45 billion last year. J&J markets the drug in the USA, while Merck sells it in Europe and elsewhere. The companies have the same arrangements for Simponi.