Statement of Changes in Beneficial Ownership (4)

FORM 4 [ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person * Azoy Alexander	2. Issuer Name and Ticker or Trading Symbol Sienna Biopharmaceuticals, Inc. [ SNNA ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director                      _____ 10% Owner __ X __ Officer (give title below)      _____ Other (specify below) Chief Financial Officer
(Last)          (First)          (Middle) 30699 RUSSELL RANCH ROAD, SUITE 140	3. Date of Earliest Transaction (MM/DD/YYYY) 8/6/2019
(Street) WESTLAKE VILLAGE, CA 91362 (City)        (State)        (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) _ X _ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. Code (Instr. 8)		4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	8/6/2019		A		70000.00	A	(1)	105948.00	D

Table II - Derivative Securities Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Options (Right to buy)	$20.19	8/6/2019		D   (2)			25000.00	(3)	12/1/2027	Common Stock	25000.00	(2)	0.00	D
Stock Options (Right to buy)	$15.08	8/6/2019		D   (2)			5600.00	(4)	6/1/2028	Common Stock	5600.00	(2)	0.00	D
Stock Options (Right to buy)	$2.37	8/6/2019		D   (2)			20000.00	(5)	4/1/2029	Common Stock	20000.00	(2)	0.00	D
Stock Options (Right to buy)	$2.32	8/6/2019		D   (2)			8750.00	(6)	1/1/2029	Common Stock	8750.00	(2)	0.00	D
Stock Options (Right to buy)	$2.32	8/6/2019		D   (2)			8750.00	(7)	1/1/2029	Common Stock	8750.00	(2)	0.00	D
Stock Options (Right to buy)	$0.71	8/6/2019		A   (2)		25000.00		(3)	12/1/2027	Common Stock	25000.00	(2)	25000.00	D
Stock Options (Right to buy)	$0.71	8/6/2019		A   (2)		5600.00		(4)	6/1/2028	Common Stock	5600.00	(2)	5600.00	D
Stock Options (Right to buy)	$0.71	8/6/2019		A   (2)		8750.00		(6)	1/1/2029	Common Stock	8750.00	(2)	8750.00	D
Stock Options (Right to buy)	$0.71	8/6/2019		A   (2)		8750.00		(7)	1/1/2029	Common Stock	8750.00	(2)	8750.00	D
Stock Options (Right to buy)	$0.71	8/6/2019		A   (2)		20000.00		(5)	4/1/2029	Common Stock	20000.00	(2)	20000.00	D

Explanation of Responses:
(1)	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 fifty percent (50%) of the total number of RSUs on February 6, 2020, twenty-five percent (25%) of the total number of RSUs on August 6, 2020, and the remaining twenty-five percent (25%) of the total number of RSUs on February 6, 2021, in each case, subject to the Reporting Person's continued employment or service relationship with the Issuer through the applicable vesting date.
(2)	The transaction reported herein reflect a one-time stock option repricing (the "Option Repricing") that became effective on August 6, 2019 and are being reported in this manner solely to comply with the technical reporting requirements under Section 16(a) of the Securities Exchange Act of 1934. Pursuant to the Option Repricing, the exercise price of each relevant option has been amended to reduce such exercise price to $0.71. There have been no other changes to the terms of the relevant options.
(3)	Twenty-five percent (25%) of the shares subject to the option vest and become exercisable on the first anniversary measured from December 1, 2017, and the remaining shares subject to the option vest and become exercisable in 36 successive, equal monthly installments thereafter, subject to the Reporting Person's continued employment or service relationship with the Issuer on each such vesting date.
(4)	Twenty-Five percent (25%) of the shares subject to the option vest and become exercisable on the first anniversary measured from June 1, 2018, and the remaining shares subject to the option vest and become exercisable in 36 successive, equal monthly installments thereafter, subject to the Reporting Person's continued employment or service relationship with the Issuer on each such vesting date.
(5)	Twenty-five percent (25%) of the shares subject to the option vest and become exercisable on October 1,2019, twenty-five percent (25%) of the shares vest and become exercisable on April 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.
(6)	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.
(7)	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.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Azoy Alexander 30699 RUSSELL RANCH ROAD SUITE 140 WESTLAKE VILLAGE, CA 91362			Chief Financial Officer

Signatures
/s/Timothy K. Andrews, attorney-in-fact for Alexander Azoy		8/8/2019
** Signature of Reporting Person		Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note:	File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.