UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A INFORMATION

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the Securities Exchange Act of 1934 (Amendment No.    )

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Arena Pharmaceuticals, Inc.

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*** Exercise Your Right to Vote *** Important Notice Regarding the Availability of Proxy Materials for the Stockholder Meeting to Be Held on June 13, 2017. ARENA PHARMACEUTICALS, INC. ARENA PHARMACEUTICALS, INC. 6154 NANCY RIDGE DRIVE SAN DIEGO, CA 92121 E29158-P94344 Meeting Information Meeting Type: Annual Meeting For holders as of: April 24, 2017 Date: June 13, 2017 Time: 9:00 AM (Pacific Time) Location: 6154 Nancy Ridge Drive San Diego, California 92121 You are receiving this communication because you hold shares in the company named above. This is not a ballot. You cannot use this notice to vote these shares. This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. You may view the proxy materials online at www.proxyvote.com or easily request a paper copy (see reverse side). We encourage you to access and review all of the important information contained in the proxy materials before voting. See the reverse side of this notice to obtain proxy materials and voting instructions.

Voting Items The Board of Directors recommends you vote FOR the following: 1. Election of Directors Nominees: 01) Scott H. Bice, J.D. 02) Jayson Dallas, M.D. 03) Oliver Fetzer, Ph.D. 04) Amit D. Munshi 05) Garry Neil, M.D. 06) Tina Nova, Ph.D. 07) Phillip Schneider 08) Christine White, M.D. 09) Randall Woods The Board of Directors recommends you vote FOR the following proposal: 2. To approve, on an advisory basis, the compensation of our named executive officers, as disclosed in the proxy statement accompanying this notice. The Board of Directors recommends you vote 1 YEAR on the following proposal: 3. To indicate, on an advisory basis, the preferred frequency of stockholder advisory votes on the compensation of our named executive officers. The Board of Directors recommends you vote FOR proposals 4, 5, 6 and 7. 4. To approve a series of alternate amendments to our Amended and Restated Certificate of Incorporation to effect, at the option of the Board of Directors, a reverse stock split of our common stock at a reverse stock split ratio ranging from one-for-six (1:6) to one-for-ten (1:10), inclusive, with the effectiveness of one of such amendments and the abandonment of the other amendments, or the abandonment of all amendments, to be determined by the Board of Directors prior to the date of our 2018 Annual Meeting of Stockholders. 5. To approve a series of alternate amendments to our Amended and Restated Certificate of Incorporation to effect, if and only if Proposal 4 is both approved and implemented, a reduction in the total number of authorized shares of our common stock as illustrated in the table under the caption "Effects of Authorized Shares Reduction" in the section of the accompanying proxy statement entitled "Proposal 5 Approval of Reduction in the Number of Authorized Shares of Common Stock. 6. To approve the Arena Pharmaceuticals, Inc., 2017 Long Term Incentive Plan. 7. To ratify the appointment of KPMG LLP, an independent registered public accounting firm, as our independent auditors for the fiscal year ending December 31, 2017. NOTE: Such other business as may properly come before the meeting or any adjournment thereof. E29160-P94344

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