X0306 4 2017-01-26 0 0001437402 ARDELYX, INC. ARDX 0001688485 Seeto Reginald C/O ARDELYX, INC. 34175 ARDENWOOD BLVD, SUITE 200 FREMONT CA 94555 0 1 0 0 Chief Operating Officer Stock Option (Right to Buy) 13.90 2017-01-26 4 A 0 26511 0.00 A 2027-01-26 Common Stock 26511 26511 D The option becomes exercisable as it vests and the shares subject to the option vest in 48 successive, equal monthly installments on each monthly anniversary of January 19, 2017, subject to the Reporting Person's continued employment or service relationship with the Issuer on each such vesting date. /s/ Elizabeth Grammer, Attorney-in-Fact for Reginald Seeto 2017-01-27