The multinational bio-pharmaceutical company is believed to have briefed Lexington to work on its market access, corporate and brand public affairs account, effective immediately. The move follows a competitive pitch for the six-figure business.
Celgene has previously only worked with agencies on a project-by-project basis, mainly for public affairs briefs. These include Helen Johnson Consulting, which covered ad hoc work during 2012.
Celgene focuses on the discovery and development of products for the treatment of cancer and other severe immune conditions.
Lexington recently established an international healthcare practice under Joanne Bullen.
Bullen, who joined from APCO Worldwide in February as international healthcare director, now works alongside UK healthcare director Jessica Fine.
Bullen worked for APCO for eight years, as director of healthcare in its London office and joint head of its EMEA healthcare practice.
Lexington co-founder Ian Kennedy said that the agency has a number of healthcare clients who are responding to challenges on an international basis.
In September last year, FTSE 250-listed construction and support service group Interserve brought in Lexington to support its government relations.
Both Lexington and Celgene declined to comment on the appointment.