X0306 4 2022-02-02 false 0001395937 Syndax Pharmaceuticals Inc SNDX 0001664204 Meyers Michael L. C/O SYNDAX PHARMACEUTICALS, INC. 35 GATEHOUSE DRIVE, BUILDING D, FLOOR 3 WALTHAM MA 02451 false true false false SVP, Chief Medical Officer Common Stock 2022-01-31 4 J false 1714.00 12.39 A 23280.00 D Stock Options (Right to buy) 15.79 2022-02-02 4 A false 17350.00 15.79 A 2032-02-02 Common Stock 17350.00 17350.00 D The Reporting Person is voluntarily filing this Form 4 to report the acquisition of 1,715 shares by the Reporting Person on 1/31/22 pursuant to the Issuer's Employee Stock Purchase Plan. 1/23rd of the shares subject to the option shall vest monthly over a two-year period. /s/ Michael A. Metzger, Attorney-in-Fact 2022-02-03