UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): July 2, 2021

MIRATI THERAPEUTICS, INC.

(Exact name of registrant as specified in its charter)

3545 Cray Court

San Diego, California 92121

(Address of principal executive offices and zip code)

Registrant’s telephone number, including area code: (858) 332-3410

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 or Rule 12b-2 of the Securities Exchange Act of 1934.

Emerging growth company  ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ☐

On July 2, 2021, Mirati Therapeutics, Inc. (“we,” “Mirati” or the “Company”) entered into an amended and restated sales agreement (the “Sales Agreement”) with Cowen and Company, LLC (“Cowen”), pursuant to which the Company may, from time to time, sell shares of the Company’s common stock, par value $0.001 per share (the “Shares”), having an aggregate offering price of up to $500,000,000 through or to Cowen, as the Company’s agent and/or principal.

Subject to the terms and conditions of the Sales Agreement, Cowen will use its commercially reasonable efforts to sell the Shares from time to time, based upon the Company’s instructions. The Company has provided Cowen with customary indemnification rights, and Cowen will be entitled to a commission of up to 3.0% of the gross sales price of the Shares sold through it pursuant to the Sales Agreement.

The Shares will be offered and sold by the Company pursuant to its shelf registration statement on Form S-3ASR (the “S-3 Registration Statement”), which became automatically effective upon filing with the Securities and Exchange Commission (the “SEC”) on July 2, 2021. The Shares may be offered only by means of a prospectus, including a prospectus supplement, forming a part of the S-3 Registration Statement. Sales of the Shares, if any, under the Sales Agreement may be made in transactions that are deemed to be “at the market offerings” as defined in Rule 415 under the Securities Act of 1933, as amended, including sales made by means of ordinary brokers’ transactions, including on The Nasdaq Global Select Market, at market prices or as otherwise agreed with Cowen. The Company has no obligation to sell any of the Shares, and may at any time suspend offers under the Sales Agreement or terminate the Sales Agreement.

The foregoing description of the Sales Agreement does not purport to be complete and is qualified in its entirety by reference to the full Sales Agreement, a copy of which is filed as Exhibit 1.2 to the S-3 Registration Statement.

This Current Report on Form 8-K does not constitute an offer to sell the Shares or a solicitation of an offer to buy the Shares, nor shall there be any sale of the Shares in any state or jurisdiction in which such an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.