Arena Pharmaceuticals Appoints Jennifer Jarrett to Board of Directors

SAN DIEGO, June 14, 2017

"We are excited to have someone with Jennifer's financial, business and strategic experience joining our board at such an important time," said Tina Nova, Chairman of the Board of Directors of Arena. "We are confident that her vast industry insights and business development, operational and financial expertise will be highly beneficial to Arena as we continue to advance our promising pipeline and plan for key clinical milestones in 2017."

Ms. Jarrett currently serves as Chief Business Officer and Chief Financial Officer of Arcus Biosciences, a biotechnology company developing next generation cancer immunotherapies. Prior to Arcus, she was Chief Financial Officer of Medivation, which was acquired by Pfizer in 2016. Before Medivation, Ms. Jarrett spent 20 years in investment banking, most recently at Citigroup, where she ran the firm's west coast life sciences investment banking practice, and prior to that at Credit Suisse and Donaldson, Lufkin & Jenrette. In 2014, she was named one of the Most Influential Women in Bay Area Business by the San Francisco Business Times. Ms. Jarrett received a Bachelor of Arts in economics from Dartmouth College and an MBA from Stanford Graduate School of Business.

About Arena Pharmaceuticals
At Arena, we are focused on developing novel, small molecule drugs with optimized receptor pharmacology designed to deliver broad clinical utility across multiple therapeutic areas. Our proprietary pipeline includes potentially first- or best-in-class programs for which we own global commercial rights.  Our three most advanced investigational clinical programs are ralinepag (APD811) in Phase 2 evaluation for pulmonary arterial hypertension (PAH), etrasimod (APD334) in Phase 2 evaluation for multiple autoimmune indications including ulcerative colitis (UC), and APD371 in Phase 2 evaluation for the treatment of pain associated with Crohn's disease. In addition, we have collaborations with the following pharmaceutical companies: Eisai Co., Ltd. and Eisai Inc. (commercial stage), Axovant Sciences (Phase 2 candidate), and Boehringer Ingelheim International GmbH (preclinical candidate).

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 the significance and participation of the appointment of Ms. Jarrett; Arena's focus, and the potential of its programs and collaborations.  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 those 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.

Corporate Contact                                                   
Kevin R. Lind
Chief Financial Officer                                  
klind@arenapharm.com                                                                     
858.210.3636

Media Contact
Matt Middleman, M.D.
LifeSci Public Relations
matt.middleman@lifescipublicrelations.com
646.627.8384