Arena Pharmaceuticals (ARNA) 10-Q 2002 Q3 Quarterly report

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Exhibit 99.1

CERTIFICATION OF CEO AND CFO PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

        In connection with the Quarterly Report on Form 10-Q of Arena Pharmaceuticals, Inc. (the "Company") for the quarterly period ended September 30, 2002, as filed with the Securities and Exchange Commission on the date hereof (the "Report"), Jack Lief, as President and Chief Executive Officer of the Company, and Joseph F. Mooney, as Chief Financial Officer of the Company, each hereby certifies, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

1.

the Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and



2.

the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ JACK LIEFJack Lief
President and Chief Executive Officer
Date: November 14, 2002 /s/ JOSEPH F. MOONEYJoseph F. Mooney
Chief Financial Officer
Date: November 14, 2002

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CERTIFICATION OF CEO AND CFO PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002