Schering-Plough says that it has taken up an option with Johnson & Johnson subsidiary Centocor to co-develop one of the latter firm’s new rheumatoid arthritis drugs.

CNTO 148 is a fully human monoclonal antibody, which is expected to move into

Phase III trials in early 2006 and is being developed as a treatment for RA and other immune-mediated inflammatory diseases. S-P has exercised its right to be involved with the new drug as it falls under a 1998 agreement signed with Centocor, a year before it was taken over by J&J.

That particular deal also gave S-P marketing rights outside the USA to Centocor’s RA drug Remicade (infliximab), a move that proved highly profitable for the Kenilworth, New Jersey-based firm with second-quarter sales reaching $234 million, a rise of nearly 30%.

With this latest agreement, S-P and Centocor will share future development and marketing expenses related to the compound and the former announced that it will take a third-quarter charge of $125 million to reimburse Centocor for the R&D it has already done. S-P will get the marketing rights to sell the new drug, if all goes well, outside the USA, Japan, China Taiwan and Indonesia.

There is, however, some disagreement between the firms as to when the agreement will expire. Centocor believes its partner’s marketing rights will end in 2014, but S-P says they do not expire until later, though “steps are being taken to resolve the difference of opinion.”