X0306 4 2018-11-02 1 0001434868 Esperion Therapeutics, Inc. ESPR 0001465837 Boxer Capital, LLC 11682 EL CAMINO REAL, SUITE 320 SAN DIEGO CA 92130 0 0 1 0 0001465836 Boxer Asset Management Inc. C/O CAY HOUSE EP TAYLOR DRIVE N7776, LYFORD CAY NEW PROVIDENCE C5 BAHAMAS 0 0 1 0 0001015747 LEWIS JOSEPH C/O CAY HOUSE EP TAYLOR DRIVE N7776, LYFORD CAY NEW PROVIDENCE C5 BAHAMAS 0 0 1 0 Common Stock 2018-11-02 4 S 0 2500 54.65 D 1198750 D Common Stock 2018-11-02 4 S 0 37500 55.25 D 1161250 D Common Stock 2018-11-05 4 S 0 26500 55.21 D 1134750 D Common Stock 2018-11-05 4 S 0 6500 56.19 D 1128250 D Common Stock 2018-11-05 4 S 0 2000 57.38 D 1126250 D Common Stock 2018-11-05 4 S 0 6390 58.82 D 1119860 D Common Stock 2018-11-05 4 S 0 13610 59.48 D 1106250 D Common Stock 2018-11-05 4 S 0 5000 60.28 D 1101250 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., (iv) Tuesday Thirteen Inc. and (v) Joseph C. Lewis (collectively, the "Boxer Group"). 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. These securities are owned indirectly by Boxer Management and Joseph C. Lewis, by virtue of their ownership of Boxer Capital. 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 $54.53 to $54.68. 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 $55.01 to $55.90. 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 $54.84 to $55.83. 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 $55.94 to $56.60. 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 $57.00 to $57.78. 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 $59.37 to $59.65. Boxer Capital, LLC, By: /s/ Aaron Davis, Chief Executive Officer 2018-11-05 Boxer Asset Management Inc., By: /s/ Jason Callender, Director 2018-11-05 /s/ Joseph C. Lewis 2018-11-05