X0306 4 2019-04-04 0 0001576263 Mirati Therapeutics, Inc. MRTX 0001663609 Dissanayake Shehan Bharatha 11682 EL CAMINO REAL, SUITE 320 SAN DIEGO CA 92130 0 0 1 0 Common Stock 2019-04-04 4 J 0 126716 0.00 D 203754 D Reflects 126,716 shares received by Shehan B. Dissanayake in connection with the transfer by MVA Investors, LLC ("MVA Investors") on April 4, 2019 of 180,926 shares of the common stock of the issuer, on a pro rata basis for no consideration. These securities are owned directly by the reporting person, which has sole voting and dispositive power with respect to these securities. The reporting person 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, LLC ("Boxer Capital"), (iii) Boxer Asset Management Inc. ("Boxer Management"), (iv) 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) the reporting person, and (xii) Christopher Fuglesang (collectively, the "Boxer Group). Each member of the Boxer Group other than the reporting person disclaims beneficial ownership of these securities to the extent it or he does not have a pecuniary interest therein. /s/ Shehan B. Dissanayake 2019-04-08