Sec Form 4 Filing - RA CAPITAL MANAGEMENT, LLC @ Satsuma Pharmaceuticals, Inc. - 2019-09-17

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 Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person RA CAPITAL MANAGEMENT, LLC 2. Issuer Name and Ticker or Trading Symbol Satsuma Pharmaceuticals, Inc. [ STSA] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 200 BERKELEY STREET, 18TH FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 09/17/2019 (Street) BOSTON, MA02116 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 09/17/2019 C 2,008,409 ( 1 ) A 2,008,409 I See footnote ( 3 ) ( 4 ) Common Stock 09/17/2019 C 1,340,116 ( 1 ) A 3,348,525 I See footnote ( 3 ) ( 4 ) Common Stock 09/17/2019 P 1,333,333 ( 5 ) A $ 15 4,681,858 ( 6 ) I See footnote ( 3 ) ( 4 )

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 7. Title and Amount of Underlying Securities (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 Series A Preferred Stock ( 2 ) 09/17/2019 C 2,008,409 ( 1 ) ( 2 ) ( 2 ) Common Stock 2,008,409 ( 7 ) ( 2 ) 0 I See footnote ( 3 ) ( 4 ) Series B Preferred Stock ( 2 ) 09/17/2019 C 1,340,116 ( 1 ) ( 2 ) ( 2 ) Common Stock 1,340,116 ( 8 ) ( 2 ) 0 I See footnote ( 3 ) ( 4 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other RA CAPITAL MANAGEMENT, LLC 200 BERKELEY STREET, 18TH FLOOR BOSTON, MA02116 X X RA Capital Healthcare Fund LP 200 BERKELEY STREET, 18TH FLOOR BOSTON, MA02116 X Kolchinsky Peter 200 BERKELEY STREET, 18TH FLOOR BOSTON, MA02116 X Signatures /s/ Peter Kolchinsky, Manager of RA Capital Management, LLC 09/17/2019 Signature of Reporting Person Date /s/ Peter Kolchinsky, Manager of RA Capital Management, LLC, the General Partner of RA Capital Healthcare Fund, L.P. 09/17/2019 Signature of Reporting Person Date /s/ Peter Kolchinsky, individually 09/17/2019 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Reflects a 1-for-4.7 reverse stock split effective upon the effectiveness of the registration statement for the issuer's initial public offering. ( 2 )Each share of Series A Preferred Stock and Series B Preferred Stock automatically converted into a share of the issuer's Common Stock, for no additional consideration, on a 1:1 basis at the consummation of issuer's initial public offering. ( 3 )RA Capital Management, LLC (the "Adviser") is the general partner of the RA Capital Healthcare Fund, L.P.(the "Fund") and the investment adviser for an account owned by a separately managed account (the "Account"). Peter Kolchinsky is the sole manager of the Adviser. The Adviser and Dr. Kolchinsky may be deemed indirect beneficial owners of the securities and they disclaim beneficial ownership of the reported securities: (A) in reliance on Rule 16a-1(a)(1)(v) and (vii); and (B) held by the Fund, for purposes of Rule 16a-1(a)(2), except to the extent of their pecuniary interest therein. ( 4 )The Adviser and Dr. Kolchinsky have no pecuniary interest in the reported securities held in the Account and disclaim: (A) beneficial ownership thereof for purposes of Rule 16a-1(a)(2); and (B) any obligation to file reports under Section 16 other than as a director by deputization. The filing of this Form 4 shall not be construed as an admission that either the Adviser or Dr. Kolchinsky is or was for the purposes of Section 16(a), or otherwise, the beneficial owner of any of the securities held in the Account. ( 5 )Includes (a) 1,140,946 shares of Common Stock held by the Fund and (b) 192,387 held in the Account, in each case acquired in the issuer's initial public offering. ( 6 )These securities include 3,923,460 shares held by the Fund and 758,398 shares held in the Account. ( 7 )Represents 1,642,879 shares held by the Fund and 365,530 shares held in the Account. ( 8 )Represents 1,139,635 shares held by the Fund and 200,481 shares held in the Account.

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.