X0206 3 2019-03-04 0 0001707502 Solid Biosciences Inc. SLDB 0001465837 Boxer Capital, LLC 11682 EL CAMINO REAL, SUITE 320 SAN DIEGO CA 92130 0 0 1 0 0001465836 Boxer Asset Management Inc. CAY HOUSE, EP TAYLOR DRIVE N7776 LYFORD CAY NEW PROVIDENCE C5 BAHAMAS 0 0 1 0 0001642355 Braslyn Ltd. CAY HOUSE, EP TAYLOR DRIVE N7776 LYFORD CAY NEW PROVIDENCE C5 BAHAMAS 0 0 1 0 0001015747 LEWIS JOSEPH CAY HOUSE, EP TAYLOR DRIVE N7776 LYFORD CAY NEW PROVIDENCE C5 BAHAMAS 0 0 1 0 0001468223 MVA Investors, LLC 11682 EL CAMINO REAL, SUITE 320 SAN DIEGO CA 92130 0 0 1 0 Common Stock 3923272 D Common Stock 11488 D Common Stock 30210 D 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. ("Braslyn"), (iv) Joseph C. Lewis and (v) MVA Investors, LLC ("MVA Investors") (collectively, the "Boxer Group"), and indirectly by Boxer Management and Joseph C. Lewis by virtue of their ownership in Boxer Capital. Each member of the Boxer Group other than Boxer Capital disclaims beneficial ownership of these securities to the extent it or he does not have a pecuniary interest therein. These securities are owned directly by Braslyn and indirectly by Joseph C. Lewis, who is the sole indirect owner of and controls Braslyn. Each member of the Boxer Group other than Braslyn disclaims beneficial ownership of these securities to the extent it or he does not have a pecuniary interest therein. These securities are owned directly and solely by MVA Investors, which has sole voting and dispositive power with respect to these securities. Each member of the Boxer Group other than MVA Investors disclaims beneficial ownership of these securities to the extent it or he does not have a pecuniary interest therein. Boxer Capital, LLC, By: /s/ Aaron I. Davis, Chief Executive Officer 2019-03-06 Boxer Asset Management Inc., By: /s/ Jason C. Callender, Director 2019-03-06 MVA Investors, LLC, By: /s/ Aaron I. Davis, Chief Executive Officer 2019-03-06 Braslyn Ltd., By: /s/ Joseph C. Lewis, Director 2019-03-06 /s/ Joseph C. Lewis 2019-03-06