BMS called in the agency after a pitch earlier this year to promote the drug, which is nearing the end of phase-III trials.
Last month the latest data was published demonstrating the long-term efficacy of the treatment.
The market for rheumatoid arthritis therapeutics has experienced particularly strong growth in the past five years and BMS has great hopes for Orencia. BMS filed for European approval for the drug earlier this year.
The drug is already approved in the US, where it is also promoted by CCA.
BMS is using start-up agency Just Health PR - which was co-founded by ex-CCA seniors Jennie Talman and Emma Crozier ten months ago (PRWeek, 10 February) - on a project basis to advise on UK comms for Orencia (PRWeek, 9 November).
Rheumatoid arthritis is a common form of arthritis. Around one in 50 people will suffer from it.