CASCADIAN THERAPEUTICS, INC. (NASDAQ:CASC) Files An 8-K Entry into a Material Definitive Agreement

Item1.01

Underwriting Agreements

On January24, 2017, Cascadian Therapeutics, Inc. (the Company)
entered into two underwriting agreements (each, an Underwriting
Agreement) with Cowen and Company, LLC (Cowen) and Barclays
Capital Inc., as representatives of the several underwriters
named therein (the Underwriters) for separate but concurrent
offerings of the Companys securities, which together are expected
to result in gross proceeds to the Company of $82.5 million.

to the first Underwriting Agreement, the Company agreed to issue
and sell an aggregate of 23,182,000 shares of its Common Stock
(the Common Stock) to the Underwriters (the Common Stock
Offering). The Common Stock will be sold at a per share public
offering price of $3.30. The sale of shares of the Companys
Common Stock is expected to close on January27, 2017. to the
first Underwriting Agreement, the Company also granted the
Underwriters a 30-day option to purchase up to an additional
3,477,300 shares of its common stock.

to the second Underwriting Agreement, the Company agreed to issue
and sell an aggregate of 1,818 shares of its Series E Convertible
Preferred Stock (the Series E Offering) to the Underwriters. The
Series E Convertible Preferred Stock will be sold at a per share
public offering price of $3,300.

The rights, preferences and privileges of the Series E
Convertible Preferred Stock are set forth in a Certificate of
Designation of Preferences, Rights and Limitations of Series E
Convertible Preferred Stock, which the Company expects to file
with the Delaware Secretary of State on or before January27,
2017. Each share of Series E Convertible Preferred Stock is
convertible into 1,000 shares of Common Stock at any time at the
holders option. The holder, however, will be prohibited from
converting Series E Convertible Preferred Stock into shares of
Common Stock if, as a result of such conversion, the holder,
together with its affiliates, would own more than 19.99% of the
shares of Common Stock then issued and outstanding, which
percentage may change at the holders election to any other number
less than or equal to 19.99% upon 61 days notice to the Company.
In the event of the Companys liquidation, dissolution, or winding
up, holders of Series E Convertible Preferred Stock will receive
a payment equal to $0.0001 per share of Series E Convertible
Preferred Stock before any proceeds are distributed to holders of
Common Stock, pari passu with any distribution of proceeds to
holders of Series A Convertible Preferred Stock, Series B
Convertible Preferred Stock, Series C Convertible Preferred Stock
and Series D Convertible Preferred Stock, and after any
distribution of proceeds to holders of ClassUA Preferred Stock.
Shares of Series E Convertible Preferred Stock will generally
have no voting rights, except as required by law and except that
the consent of holders of a majority of the outstanding Series E
Convertible Preferred Stock will be required to amend the terms
of the Series E Convertible Preferred Stock. Shares of Series E
Convertible Preferred Stock will not be entitled to receive any
dividends, unless and until specifically declared by the Companys
board of directors, and will rank:

in each case, as to distributions of assets upon the Companys
liquidation, dissolution or winding up whether voluntarily or
involuntarily.

2

Each of the Underwriting Agreements contain customary
representations, warranties and agreements by the Company,
customary conditions to closing, indemnification obligations of
the Company and the Underwriters, including for liabilities under
the Securities Act of 1933, as amended (the Securities Act),
other obligations of the parties and termination provisions. The
representations, warranties and covenants contained in the
Underwriting Agreements were made only for purposes of such
agreement and as of specific dates, were solely for the benefit
of the parties to such agreement and may be subject to
limitations agreed upon by the contracting parties. Subject to
certain exceptions, the Company and all of the Companys directors
and executive officers, other than former director Mark Lampert,
also agreed to not sell or transfer any common stock of the
Company for 60 days after January24, 2017 without first obtaining
the consent of Cowen and Company, LLC and Barclays Capital Inc.

Each of the Common Stock Offering and the Series E Offering is
being made to the Companys effective shelf registration statement
on Form S-3
(Registration No.333-201317), including the prospectus dated
January7, 2015 contained therein, as the same has been
supplemented.

A copy of the
Underwriting Agreement relating to the Common Stock Offering is
attached hereto as Exhibit 1.1 and is incorporated herein by
reference. A copy of the Underwriting Agreement relating to the
Series E Offering is attached hereto as Exhibit 1.2 and is
incorporated herein by reference. A form of the Certificate of
Designation of Preferences, Rights and Limitations of Series E
Convertible Preferred Stock is attached hereto as Exhibit 4.1 and
is incorporated by reference herein. The foregoing description of
the terms of the Underwriting Agreements and the rights,
preferences and privileges of the Series E Convertible Preferred
Stock is qualified in its entirety by reference to such exhibits.
A copy of the opinion of Fenwick West LLP relating to the
legality of the issuance and sale of the securities in these
offerings is attached as Exhibit 5.1 hereto.

Registration
Rights Agreement

In connection with
the Series E Offering, the Company intends to enter into a
registration rights agreement (the Registration Rights Agreement)
with purchasers of Series E Convertible Preferred Stock. Under
the Registration Rights Agreement, the Company will be required
to file a registration statement on FormS-3 to register the
resale of the shares issuable upon conversion of Series E
Convertible Preferred Stock within 100 days of the issuance date
of the Series E Convertible Preferred Stock. The registration
rights will terminate upon a holders sale to the registration
statement on Form S-3 or Rule144 under the Securities Act, or the
date a holders registrable shares are eligible for sale without
restriction under Rule 144. The Registration Rights Agreement
includes customary covenants of the Company and provides that the
Company will indemnify the holders and related parties against
certain losses and liabilities. The Company will bear expenses
related to the filing of the registration statement on Form S-3,
including expenses of holders counsel up to $25,000.

A copy of the
Registration Rights Agreement is attached hereto as Exhibit 10.1
and is incorporated herein by reference.

On June2, 2016,
the Company entered into a Sales Agreement (the Sales Agreement)
with Cowen to sell shares of Common Stock having aggregate sales
proceeds of $50million, from time to time, through an at the
market equity offering program (the ATM Offering) under which
Cowen acted as sales agent. A description of the Sales Agreement
was included in the Companys Current Report on Form 8-K filed
with the SEC on June2, 2016.

On January23,
2017, the Company provided notice to Cowen of its decision to
terminate the Sales Agreement, effective as of the close of
business on such date. The Company is not subject to any
termination penalties related to termination of the Sales
Agreement.

As reported in the
Companys preliminary prospectus supplements filed with the
Securities and Exchange Commission (SEC) on January23, 2017,
based on the Companys current estimates, as of December31, 2016,
the Company had approximately $63million in cash and short-term
investments. The actual amounts that the Company will report will
be subject to its financial closing procedures and any final
adjustments that may be made prior to the time its financial
results for the period ended December31, 2016 are
finalized.

3

The information in
this Item2.02 shall not be deemed to be filed for purposes of
Section18 of the Securities Exchange Act of 1934, as amended, or
otherwise subject to the liabilities of that section or
Sections11 and 12(a)(2)of the Securities Act of 1933, as
amended.The information contained in this Item2.02 shall not be
incorporated by reference into any registration statement or
other document filed by the Company with the SEC, whether made
before or after the date of this Current Report on Form8-K,
regardless of any general incorporation language in such filing
(or any reference to this Current Report on Form8-K generally),
except as shall be expressly set forth by specific reference in
such filing.

On January24,
2017, the Company issued a press release announcing the matters
described above. A copy of the press release is filed as Exhibit
99.1 and incorporated herein by reference.

(d)
Exhibits.

Forward-Looking
Statements