Hogan has joined as director of media and PR at the firm, which is behind products such as multiple-sclerosis drug Rebif and psoriasis treatment Raptiva.
When Hogan was at Cadbury she had to cope with the flak that accompanied its controversial Get Active campaign in 2003.
She left the confectioner in 2004 and has since acted as a consultant for GlaxoSmithKline. Prior to Cadbury she worked for GSK, and its predecessor SmithKline Beecham, in the US.
Hogan has replaced Michael George, who left for Ferring (PRWeek, 6 May).