SEC FORM 4 SEC Form 4
FORM 4 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
1. Name and Address of Reporting Person*
Burow Kristina

(Last) (First) (Middle)
8755 WEST HIGGINS ROAD
SUITE 1025

(Street)
CHICAGO IL 60631

(City) (State) (Zip)
2. Issuer Name and Ticker or Trading Symbol
Sienna Biopharmaceuticals, Inc. [ SNNA ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
X Director 10% Owner
Officer (give title below) Other (specify below)
3. Date of Earliest Transaction (Month/Day/Year)
02/22/2019
4. If Amendment, Date of Original Filed (Month/Day/Year)
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. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction 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 02/22/2019 P 150,000 A $2.5 2,900,575 I See footnote(1)
Common Stock 02/22/2019 P 150,000 A $2.5 1,032,493 I See footnote(2)
Common Stock 02/22/2019 P 1,865,800 A $2.5 1,865,800 I See footnote(3)
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction 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 (Month/Day/Year) 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: 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
Explanation of Responses:
1. The shares are directly held of record by ARCH Venture Fund VIII, L.P. ("ARCH Fund VIII"). The sole general partner of ARCH Fund VIII is ARCH Venture Partners VIII, L.P. ("ARCH Partners VIII"). The sole general partner of ARCH Partners VIII is ARCH Venture Partners VIII, LLC ("ARCH VIII LLC"). ARCH Partners VIII and ARCH VIII LLC may therefore be deemed to beneficially own the securities held by ARCH Fund VIII. The Reporting Person has an interest in ARCH Partners VIII and ARCH VIII LLC, but does not have voting or investment control over the shares held by ARCH Fund VIII. The Reporting Person disclaims beneficial ownership of such shares except to the extent of any pecuniary interest therein.
2. The shares are directly held of record by ARCH Venture Fund VIII Overage, L.P. ("ARCH Fund Overage"). The sole general partner of ARCH Fund Overage is ARCH VIII LLC. ARCH VIII LLC may therefore be deemed to beneficially own the securities held by ARCH Fund Overage. The Reporting Person has an interest in ARCH VIII LLC, but does not have voting or investment control over the shares held by ARCH Fund Overage. The Reporting Person disclaims beneficial ownership of such shares except to the extent of any pecuniary interest therein.
3. The shares are directly held of record by ARCH Venture Fund X Overage, L.P. ("ARCH X Overage"). The sole general Partner of ARCH X Overage is ARCH Venture Partners X Overage, L.P. ("AVP X Over GP"). The sole general partner of AVP X Over GP is ARCH Venture Partners X, LLC ("AVP X LLC"). AVP X Over LP and AVP X LLC may therefore be deemed to beneficially own the securities held by ARCH X Overage. AVP X Over GP and AVP X LLC disclaim beneficial ownership of such securities, except to the extent of any pecuniary interest therein. The Reporting Person is a managing director of AVP X LLC and may be deemed to beneficially own the shares held by ARCH X Overage. The Reporting Person disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein.
Remarks:
/s/ Mark McDonnell, Attorney-in-Fact for Kristina Burow 02/26/2019
** 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 Number.
POWERS OF ATTORNEY



KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears 

below hereby constitutes and appoints Mark McDonnell his or its true and 

lawful attorney-in-fact, with full power of substitution, to sign any and 

all instruments, certificates and documents that may be necessary, desirable 

or appropriate to be executed on behalf of himself as an individual or in 

his capacity as a direct or indirect general partner, member, director, 

officer or manager of any partnership, corporation or limited liability 

company, pursuant to section 13 or 16 of the Securities Exchange Act of 1934, 

as amended (the "Exchange Act"), and any and all regulations promulgated 

thereunder, and to file the same, with all exhibits thereto, and any other 

documents in connection therewith, with the Securities and Exchange Commission, 

and with any other entity when and if such is mandated by the Exchange Act or 

by the Financial Industry Regulatory Authority, granting unto said 

attorney-in-fact full power and authority to do and perform each and every 

act and thing necessary, desirable or appropriate, fully to all intents and 

purposes as he might or could do in person, thereby ratifying and confirming 

all that said
 attorney-in-fact, or his substitutes, may lawfully do or cause 

to be done by virtue hereof.  This Power of Attorney shall remain in full force 

and effect with respect to each undersigned person unless and until six months 

after such person is both no longer a Managing Director of ARCH Venture Partners

and no longer serving on the board of directors of any portfolio company of any 

ARCH Venture Partners fund.



IN WITNESS WHEREOF, this Power of Attorney has been signed as of the 21th day 

of February, 2019.



ARCH VENTURE FUND X, L.P.



By: ARCH Venture Partners X, L.P.

its General Partner

By: ARCH Venture Partners X, LLC

its General Partner  

By: /s/ Keith Crandell                          

Managing Director



ARCH VENTURE PARTNERS X, L.P.



By: ARCH Venture Partners X, LLC

its General Partner  

By: /s/ Keith Crandell                                                    

Managing Director



ARCH VENTURE FUND X OVERAGE, L.P.



By: ARCH Venture Partners X Overage, L.P.

its General Partner

By: ARCH Venture Partners X, LLC

its General Partner  

By: /s/ Keith Crandell                          

Managing Director



ARCH VENTURE PARTNERS X OVERAGE, L.P.



By: ARCH Venture Partners X, LLC

its General Partner  

By: /s/ Keith Crandell                                                    

Managing Director



ARCH VENTURE PARTNERS X, LLC



By: /s/Keith Crandell                          

Managing Director



/s/ Keith Crandell                          

Keith Crandell



/s/ Kristina Burow

Kristina Burow

  

/s/ Robert Nelsen

Robert Nelsen



/s/ Steven Gillis

Steven Gillis