Sec Form 4 Filing - Boxer Capital, LLC @ Solid Biosciences Inc. - 2019-03-26

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 Boxer Capital, LLC 2. Issuer Name and Ticker or Trading Symbol Solid Biosciences Inc. [ SLDB] 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) 11682 EL CAMINO REAL, SUITE 320 3. Date of Earliest Transaction (MM/DD/YY) 03/26/2019 (Street) SAN DIEGO, CA92130 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 03/26/2019 S 275,000 D $ 10.08 ( 2 ) 3,648,272 D ( 1 ) Common Stock 03/27/2019 S 115,000 D $ 9.6 ( 3 ) 3,533,272 D ( 1 ) Common Stock 03/28/2019 S 60,000 D $ 9.53 ( 4 ) 3,473,272 D ( 1 )

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 Boxer Capital, LLC 11682 EL CAMINO REAL, SUITE 320 SAN DIEGO, CA92130 X Signatures Boxer Capital, LLC, By: /s/ Aaron Davis, Aaron Davis, Chief Executive Officer 03/28/2019 Signature of Reporting Person Date

Explanation of Responses:

( 1 )These securities are owned directly by Boxer Capital, LLC ("Boxer Capital"), which may be deemed to be a member of a "group" for purposes of Section 13(d) of the Securities Exchange Act of 1934, as amended, consisting of (i) Boxer Capital, (ii) Boxer Asset Management Inc. ("Boxer Management"), (iii) Braslyn Ltd., (iv) Joseph C. Lewis and (v) MVA Investors, LLC (collectively, the "Boxer Group"), and indirectly by Boxer Management and Mr. Lewis. Each member of the Boxer Group other than Boxer Capital disclaims beneficial ownership of these securities to the extent it does not have a pecuniary interest therein. ( 2 )Reflects the weighted average sale price. The reporting person effected multiple same-way open market sale transactions on the same day at different prices through a trade order executed by a broker dealer. The reporting person reported on a single line all such transactions that occurred within a one dollar price range. The reporting person hereby undertakes to provide upon request by the Securities and Exchange Commission staff, the issuer, or a shareholder of the issuer, full information regarding the number of shares sold at each separate price. The range of prices for such transaction is $10.00 to $10.13. ( 3 )Reflects the weighted average sale price. The reporting person effected multiple same-way open market sale transactions on the same day at different prices through a trade order executed by a broker dealer. The reporting person reported on a single line all such transactions that occurred within a one dollar price range. The reporting person hereby undertakes to provide upon request by the Securities and Exchange Commission staff, the issuer, or a shareholder of the issuer, full information regarding the number of shares sold at each separate price. The range of prices for such transaction is $9.53 to $9.80. ( 4 )Reflects the weighted average sale price. The reporting person effected multiple same-way open market sale transactions on the same day at different prices through a trade order executed by a broker dealer. The reporting person reported on a single line all such transactions that occurred within a one dollar price range. The reporting person hereby undertakes to provide upon request by the Securities and Exchange Commission staff, the issuer, or a shareholder of the issuer, full information regarding the number of shares sold at each separate price. The range of prices for such transaction is $9.52 to $9.55.

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).

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