X0306 4 2019-01-01 false 0001656328 Sienna Biopharmaceuticals, Inc. SNNA 0001559583 Smither John W C/O SIENNA BIOPHARMACEUTICALS, INC. 30699 RUSSELL RANCH ROAD, SUITE 140 WESTLAKE VILLAGE CA 91362 false true false false Chief Financial Officer Common Stock 2019-01-01 4 A false 45000.00 A 46657.00 D Common Stock 34961.00 I See Footnote Stock Options (Right to buy) 2.32 2019-01-01 4 A false 14422.00 0.00 A 2019-01-01 2029-01-01 Common Stock 14422.00 14422.00 D Stock Options (Right to buy) 2.32 2019-01-01 4 A false 22500.00 0.00 A 2029-01-01 Common Stock 22500.00 22500.00 D Stock Options (Right to buy) 2.32 2019-01-01 4 A false 22500.00 0.00 A 2029-01-01 Common Stock 22500.00 45000.00 D Award of restricted stock units ("RSUs") granted under the Issuer's 2017 Incentive Award Plan. Each RSU entitles the Reporting Person to receive one share of Issuer common stock upon vesting. The award vests as to twenty-five percent (25%) of the total number of RSUs on July 1, 2019, twenty-five percent (25%) of the total number of RSUs on January 1, 2020, and the remaining fifty percent (50%) of the total number of RSUs on the second anniversary, in each case, subject to the Reporting Person's continued employment or service relationship with the Issuer through the applicable vesting date. Includes a total of 1,657 shares of the Issuer's common stock acquired pursuant to the Issuer's Employee Stock Purchase Plan. The shares are directly held by the 1994 Smither Family Trust, as Amended and Restated in 2014. Twenty percent (20%) of the shares subject to the option vest and become exercisable upon satisfaction of one performance-based milestone, forty percent (40%) of the shares vest and become exercisable upon satisfaction of a second performance-based milestone, and the remaining forty percent (40%) of the shares vest and become exercisable upon satisfaction of a third performance-based milestone, subject to the Reporting Person's continued employment or service relationship with the Issuer on each such vesting date. Twenty-five percent (25%) of the shares subject to the option vest and become exercisable on July 1,2019, twenty-five percent (25%) of the shares vest and become exercisable on January 1, 2020, and the remaining shares vest and become exercisable in 12 successive, equal monthly installments thereafter, subject to the Reporting Person's continued employment or service relationship with the Issuer on each such vesting date. /s/ Timothy K. Andrews, attorney-in-fact for John W. Smither 2019-01-03