X0306 4 2019-01-08 0 0001576263 Mirati Therapeutics, Inc. MRTX 0001465837 Boxer Capital, LLC 11682 EL CAMINO REAL, SUITE 320 SAN DIEGO CA 92130 0 0 1 0 Common Stock 2019-01-08 4 S 0 150000 50.70 D 1415560 D Common Stock 2019-01-08 4 S 0 123800 51.56 D 1291760 D Common Stock 2019-01-08 4 S 0 233303 52.88 D 1058457 D Common Stock 2019-01-08 4 S 0 42897 54.36 D 1015560 D Common Stock 2019-01-08 4 F 0 12 48.28 D 1015548 D Common Stock 2019-01-08 4 M 0 550012 0.001 A 1565560 D Common Stock 2019-01-09 4 S 0 20000 50.21 D 1545560 D Common Stock 2019-01-09 4 S 0 80000 51.43 D 1465560 D Common Stock 2019-01-09 4 S 0 50000 52.27 D 1415560 D Common Stock 2019-01-09 4 F 0 3 50.89 D 1415557 D Common Stock 2019-01-09 4 M 0 150003 0.001 A 1565560 D Warrant (right to purchase) 0.001 2019-01-08 4 M 0 550012 5.599 D 2017-01-06 Common Stock 550012 1791774 D Warrant (right to purchase) 0.001 2019-01-09 4 M 0 150003 5.599 D 2017-01-06 Common Stock 150003 1641771 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) Braslyn Ltd. ("Braslyn"), (ii) Boxer Capital, (iii) Boxer Asset Management Inc. ("Boxer Management"), (iv) MVA Investors, LLC ("MVA Investors"), (v) Tuesday Thirteen Inc., (vi) Joe Lewis, (vii) Rodney W. Lappe, (viii) Ivan M. Lieberburg, (ix) Aaron I. Davis, (x) Neil Reisman, (xi) Shehan B. Dissanayake, and (xii) Christopher Fuglesang (collectively, the "Boxer Group), and indirectly by Boxer Management and Messrs. Lewis, Fuglesang, Reisman, Lieberburg, Dissanayake and Davis, by virtue of their ownership in Boxer Capital. Each of Messrs. Fuglesang, Reisman, Lieberburg, Dissanayake and Davis is a member of Boxer Capital. (Continued from Footnote 1) 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. 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 $50.14 to $51.01. 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 $51.46 to $52.01. 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 $52.68 to $53.08. 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 $54.00 to $54.54. 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 $49.89 to $50.74. 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 $50.98 to $51.74. 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 $52.25 to $52.35. The warrants do not have an expiration date and are not exercisable to the extent that, following exercise of such warrants, the warrant holder and its affiliates would beneficially own more than 19.99% of the issuer's common stock. Boxer Capital, LLC, By: /s/ Aaron Davis 2019-01-09