UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 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): June 8, 2017

CASCADIAN THERAPEUTICS, INC.

(Exact name of registrant as specified in its charter)

2601 Fourth Avenue, Suite 500

Seattle, Washington 98121

(Address of principal executive offices, including zip code)

(206) 801-2100

(Registrant’s telephone number, including area code)

(Former name or former address, if changed since last report)

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):

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

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.  ☐

As noted below, on June 8, 2017, the stockholders of Cascadian Therapeutics, Inc. (the “Company”) approved an amendment to the Company’s certificate of incorporation to increase the number of the Company’s authorized shares of common stock from 66,666,667 to 130,000,000. On June 8, 2017, the Company filed the Certificate of Amendment to the Amended and Restated Certificate of Incorporation with the Delaware Secretary of State to effect such amendment. A copy of the Certificate of Amendment to the Amended and Restated Certificate of Incorporation is filed as Exhibit 3.1 to this report.

The Annual Meeting of Stockholders of the Company was held on June 8, 2017. The following is a brief description of each matter voted upon and the certified voting results.

(1) Election of the nominees listed below as Class I directors to the board of directors, to hold office until the 2020 Annual Meeting of Stockholders and until his successor is duly elected and qualified:

Pursuant to the foregoing votes, the nominees listed above were elected as Class I directors to serve on the Company’s board of directors.

(2) Approval of an amendment to the Company’s 2016 Equity Incentive Plan to increase the total shares of common stock available for issuance under the Company’s 2016 Equity Incentive Plan from 1,200,905 to 7,900,905:

Pursuant to the foregoing votes, this matter was approved.

(3) Approval, by a non-binding advisory vote, of a resolution approving the compensation paid by the Company to its named executive officers:

Pursuant to the foregoing votes, this matter was approved.

(4) Indication, by a non-binding advisory vote, of the preferred frequency of future non-binding advisory votes to approve the compensation paid by the Company to its named executive officers:

Pursuant to the foregoing votes, a frequency of every year was indicated as the preferred frequency. Consistent with the recommendation of the Company’s Board of Directors and the outcome of the stockholder vote regarding this proposal, the Company’s Board of Directors determined to hold an annual advisory vote to approve the compensation paid by the Company to its named executive officers.

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(5) Approval of an amendment to the Company’s certificate of incorporation to increase its authorized shares of common stock from 66,666,667 to 130,000,000:

Pursuant to the foregoing votes, this matter was approved.

(6) Ratification of the appointment of Ernst & Young LLP as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2017:

Pursuant to the foregoing votes, the appointment of Ernst & Young LLP as the Company’s independent registered public accounting firm for the fiscal year ending December 31, 2017 was ratified.

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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.

Date: June 9, 2017

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