X0306 4 2019-02-06 false 0001395937 Syndax Pharmaceuticals Inc SNDX 0001654430 Morrison Briggs C/O SYNDAX PHARMACEUTICALS, INC. 35 GATEHOUSE DRIVE, BUILDING D, FLOOR 3 WALTHAM MA 02451 true true false false Chief Executive Officer Stock Option (Right to Buy) 6.38 2019-02-06 4 A false 354000.00 0.00 A 2029-02-06 Common Stock 354000.00 354000.00 D The securities awarded on 02/06/2019 were in the form of stock options issued pursuant to the Syndax Pharmaceuticals, Inc. 2015 Omnibus Incentive Plan. Options to purchase 177,000 shares of common stock shall vest in 48 successive equal monthly installments measured from 02/06/2019. Options to purchase 177,000 shares of common stock shall vest periodically upon the Issuer achieving certain milestones. /s/ Michael A. Metzger, Attorney-in-fact 2019-02-08