Sec Form 4 Filing - Shin Nippon Biomedical Laboratories, Ltd. @ Satsuma Pharmaceuticals, Inc. - 2023-06-06

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

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1. Name and Address of Reporting Person Shin Nippon Biomedical Laboratories, Ltd. 2. Issuer Name and Ticker or Trading Symbol Satsuma Pharmaceuticals, Inc. [ STSA] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 2438 MIYANOURA-CHO 3. Date of Earliest Transaction (MM/DD/YY) 06/06/2023 (Street) KAGOSHIMA-SHI, M0891-1394 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ 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 06/06/2023 P 22,053,581 A $ 0.91 22,053,581 ( 1 ) ( 2 ) I See Footnote ( 1 ) ( 2 ) Common Stock 2,560,780 ( 1 ) ( 4 ) D Common Stock 233,333 ( 1 ) ( 5 ) I See Footnote ( 5 ) Common Stock 06/08/2023 P 8,423,732 A $ 0.91 8,423,732 ( 1 ) ( 3 ) I See Footnote ( 1 ) ( 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 (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

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Shin Nippon Biomedical Laboratories, Ltd. 2438 MIYANOURA-CHO KAGOSHIMA-SHI, M0891-1394 X Signatures Shin Nippon Biomedical Laboratories, Ltd., By: /s/ Shinji Nitanda, Director 06/08/2023 Signature of Reporting Person Date

Explanation of Responses:

( 1 )All of the shares were cancelled on June 8, 2023 pursuant to the terms of that certain Agreement and Plan of Merger, dated as of April 16, 2023 (the "Merger Agreement"), by and among Shin Nippon Biomedical Laboratories, Ltd. ("SNBL"), SNBL23 Merger Sub, Inc., a wholly owned subsidiary of SNBL ("Merger Sub"), and Satsuma Pharmaceuticals, Inc. ("Satsuma"). Following effectiveness of the merger provided for in the Merger Agreement, SNBL owns 1000 shares of the common stock of Satsuma, which represents all of the outstanding shares of common stock of Satsuma. As a result of the merger, Satsuma became a wholly owned subsidiary of SNBL. ( 2 )Shares acquired by Merger Sub, upon acceptance of all shares validly tendered and not validly withdrawn pursuant to the tender offer by Merger Sub and SNBL, pursuant to the Merger Agreement, for any and all outstanding shares of Satsuma common stock pursuant to that certain Offer to Purchase, dated May 5, 2023. ( 3 )Shares acquired pursuant to the merger provided for in the Merger Agreement. ( 4 )SNBL acquired an aggregate of 2,560,780 shares of common stock of Satsuma in transactions on July 1, 2016, February 1, 2018, and April 22, 2019. ( 5 )SNBL U.S.A., Ltd., a wholly owned subsidiary of SNBL acquired an aggregate of 233,333 shares of common stock of Satsuma in a transaction on September 13, 2019.

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