Ownership Submission
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 OF SECURITIES

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
OMB APPROVAL
OMB Number: 3235-0287
Expires: January 31, 2005
Estimated average burden hours per response... 0.5

(Print or Type Responses)
1. Name and Address of Reporting Person *
Boxer Capital, LLC
  2. Issuer Name and Ticker or Trading Symbol
Mirati Therapeutics, Inc. [MRTX]
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 (Month/Day/Year)
01/08/2019
(Street)

SAN DIEGO, CA 92130
4. If Amendment, Date Original Filed(Month/Day/Year)
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 (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 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 01/08/2019   S   150,000 D $ 50.7 (3) 1,415,560 D (1) (2)  
Common Stock 01/08/2019   S   123,800 D $ 51.56 (4) 1,291,760 D (1) (2)  
Common Stock 01/08/2019   S   233,303 D $ 52.88 (5) 1,058,457 D (1) (2)  
Common Stock 01/08/2019   S   42,897 D $ 54.36 (6) 1,015,560 D (1) (2)  
Common Stock 01/08/2019   F   12 D $ 48.28 1,015,548 D (1) (2)  
Common Stock 01/08/2019   M   550,012 A $ 0.001 1,565,560 D (1) (2)  
Common Stock 01/09/2019   S   20,000 D $ 50.21 (7) 1,545,560 D (1) (2)  
Common Stock 01/09/2019   S   80,000 D $ 51.43 (8) 1,465,560 D (1) (2)  
Common Stock 01/09/2019   S   50,000 D $ 52.27 (9) 1,415,560 D (1) (2)  
Common Stock 01/09/2019   F   3 D $ 50.89 1,415,557 D (1) (2)  
Common Stock 01/09/2019   M   150,003 A $ 0.001 1,565,560 D (1) (2)  

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number. SEC 1474 (9-02)

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 (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 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
(Month/Day/Year)
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
Warrant (right to purchase) $ 0.001 01/08/2019   M     550,012 01/06/2017   (10) Common Stock 550,012 $ 5.599 1,791,774 D (1) (2)  
Warrant (right to purchase) $ 0.001 01/09/2019   M     150,003 01/06/2017   (10) Common Stock 150,003 $ 5.599 1,641,771 D (1) (2)  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Boxer Capital, LLC
11682 EL CAMINO REAL, SUITE 320
SAN DIEGO, CA 92130
    X    

Signatures

 Boxer Capital, LLC, By: /s/ Aaron Davis   01/09/2019
**Signature of Reporting Person Date

Explanation of Responses:

* 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).
(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) 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.
(2) (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.
(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 $50.14 to $51.01.
(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 $51.46 to $52.01.
(5) 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.
(6) 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.
(7) 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.
(8) 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.
(9) 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.
(10) 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.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.