Jack Lief

JACK LIEF is a co-Founder of Arena Pharmaceuticals, Inc., and has served
as a Director, President and Chief Executive Officer since April 1997.
Mr. Lief is also currently serving as a Director and President of Aressa
and as a director and Chief Executive Officer of ChemNavigator.com. From
1995 until April 1997, Mr. Lief served as an advisor and consultant to
numerous biopharmaceutical organizations. From 1989 to 1994, he served
as Senior Vice President, Corporate Development and Secretary of
Cephalon, Inc. From 1983 to 1989, Mr. Lief served as Director of
Business Development and Strategic Planning for Alpha Therapeutic
Corporation. Mr. Lief joined Abbott Laboratories in 1972 where he served
until 1983, most recently as the head of International Marketing
Research. Mr. Lief holds a BA from Rutgers University and an MS in
Psychology (experimental and neurobiology) from Lehigh University.