Arena Pharmaceuticals Announces the Presentation of Lorcaserin Phase 3 BLOOM Data...

Arena Pharmaceuticals Announces the Presentation of Lorcaserin Phase 3 BLOOM
Data at the American Diabetes Association's 69th Scientific Sessions

- Late-Breaking Abstract Accepted -

SAN DIEGO, June 1, 2009 /PRNewswire-FirstCall/ -- Arena Pharmaceuticals, Inc.
(Nasdaq: ARNA) announced today that a late-breaking abstract of its lorcaserin
Phase 3 BLOOM (Behavioral modification and Lorcaserin for Overweight and
Obesity Management) trial has been accepted for a poster presentation at the
American Diabetes Association's 69th Scientific Sessions in New Orleans,
Louisiana. The abstract, titled "Lorcaserin Reduces Body Weight in Obese and
Overweight Subjects: Behavioral Modification and Lorcaserin for Overweight and
Obesity Management, the BLOOM Trial," will be displayed from June 6, 2009 at
10:00 a.m. Central Daylight Time (CDT) until June 8, 2009 at 4:00 p.m. CDT in
the Morial Convention Center, Hall E. The poster has been assigned
presentation number 96-LB in category 20-B Obesity - Clinical Treatment.

Steven R. Smith, M.D., BLOOM Co-Principal Investigator and Professor and
Assistant Director for Clinical Research at the Pennington Biomedical Research
Center; William R. Shanahan, M.D., Arena's Vice President and Chief Medical
Officer; and Christen M. Anderson, M.D., Ph.D., Arena's Vice President,
Clinical Development, will be available at the poster to discuss and address
questions during two periods:

- Sunday, June 7, 2009: 6:30-7:45 p.m. CDT

- Monday, June 8, 2009: 12:00-2:00 p.m. CDT

About Lorcaserin

Lorcaserin is a novel single agent that represents the first in a new class of
selective serotonin 2C receptor agonists. The serotonin 2C receptor is located
in areas of the brain involved in the control of appetite and metabolism, such
as the hypothalamus. Stimulation of this receptor is strongly associated with
feeding behavior and satiety. Lorcaserin is currently being evaluated in a
Phase 3 program expected to enroll approximately 7,800 patients and
potentially represents a targeted treatment option for the millions of
patients who need to better manage their weight. Arena has patents that cover
lorcaserin in the US and other jurisdictions, which in most cases are capable
of continuing into 2023 without taking into account any patent term extensions
or other exclusivity Arena might obtain.

About Arena Pharmaceuticals

Arena is a clinical-stage biopharmaceutical company focused on discovering,
developing and commercializing oral drugs in four major therapeutic areas:
cardiovascular, central nervous system, inflammatory and metabolic diseases.
Arena's most advanced drug candidate, lorcaserin, is being investigated in a
Phase 3 clinical trial program for weight management. Arena's broad pipeline
of novel compounds target G protein-coupled receptors, an important class of
validated drug targets, and includes compounds being evaluated independently
and with partners, including Merck & Co., Inc., and Ortho-McNeil-Janssen
Pharmaceuticals, Inc.

Arena Pharmaceuticals(R) and Arena(R) are registered service marks of the
company. "APD" is an abbreviation for Arena Pharmaceuticals Development.

Forward-Looking Statements

Certain statements in this press release are forward-looking statements that
involve a number of risks and uncertainties. Such forward-looking statements
include statements about lorcaserin's potential to be the first in a new class
of agonists or treatment option; lorcaserin's selectivity; enrollment in the
lorcaserin Phase 3 program; lorcaserin's patent coverage; and Arena's
strategy, internal and partnered programs, and ability to develop compounds
and commercialize drugs. For such statements, Arena claims the protection of
the Private Securities Litigation Reform Act of 1995. Actual events or results
may differ materially from Arena's expectations. Factors that could cause
actual results to differ materially from the forward-looking statements
include, but are not limited to, Arena's ability to obtain additional funds;
the timing, success and cost of Arena's lorcaserin program and other of its
research and development programs; results of clinical trials or preclinical
studies may not be predictive of future results; clinical trials and studies
may not proceed at the time or in the manner Arena expects or at all; Arena's
ability to partner lorcaserin or other of its compounds or programs; the
timing and ability of Arena to receive regulatory approval for its drug
candidates; Arena's ability to obtain and defend its patents; and the timing
and receipt of payments and fees, if any, from Arena's collaborators.
Additional factors that could cause actual results to differ materially from
those stated or implied by Arena's forward-looking statements are disclosed in
Arena's filings with the Securities and Exchange Commission. These
forward-looking statements represent Arena's judgment as of the time of this
release. Arena disclaims any intent or obligation to update these
forward-looking statements, other than as may be required under applicable
law.

Contacts: Jack Lief
President and Chief Executive Officer

Cindy McGee
Senior Communications Associate

Arena Pharmaceuticals, Inc.
858.453.7200, ext. 1479

SOURCE Arena Pharmaceuticals, Inc.

Jack Lief, President and Chief Executive Officer, or Cindy McGee, Senior
Communications Associate, both of Arena Pharmaceuticals, Inc.,
+1-858-453-7200, ext. 1479