X0306 4 2022-02-02 false 0001395937 Syndax Pharmaceuticals Inc SNDX 0001653276 Huber Martin H. Jr. C/O SYNDAX PHARMACEUTICALS, INC. 35 GATEHOUSE DRIVE, BUILDING D, FLOOR 3 WALTHAM MA 02451 true false false false Common Stock 2022-02-02 4 A false 16000.00 0.00 A 16000.00 D Award of Restricted Stock Units that vests one year from the date of grant. The shares underlying such Restricted Stock Units will not be delivered to the Reporting Person and may not be transferred or sold until the earlier of a separation from service, death, disability or change in control. /s/ Michael A. Metzger, Attorney-in-Fact 2022-02-03