Thomas spent two years working for the WPP agency's UK health team, having joined from the same role at Lowe Fusion (PRWeek, 19 Nov 2004).
The role he has taken at Pfizer, which had not returned PRWeek's calls as the magazine went to press, is not known. Thomas was unavailable to comment.
Pfizer hit the headlines earlier this week when it ended development of torcetrapib, an important new cholesterol pill.
ALSO... C&W has promoted associate director Pat Hindley - who joined the agency in January 2004 - to the board. She takes responsibility for the agency's consumer health portfolio, working closely with consumer MD Claire Mann.