Atara Biotherapeutics, Inc. (NASDAQ:ATRA) Files An 8-K Entry into a Material Definitive Agreement

Item1.01.

On March27, 2017, Atara Biotherapeutics, Inc. (the Company)
entered into a sales agreement (the Agreement) with Cowen and
Company, LLC (Cowen) under which the Company may offer and sell,
from time to time at its sole discretion, shares of its common
stock, par value $0.0001 per share (the Common Stock), having an
aggregate offering price of up to $75,000,000 through Cowen as
its sales agent (the ATM Offering).

Cowen may sell the Common Stock by any method that is deemed to
be an at the market offering as defined in Rule 415 of the
Securities Act of 1933, as amended, including sales made directly
on The NASDAQ Global Select Market or any other trading market
for our common stock. Cowen will use commercially reasonable
efforts to sell the Common Stock from time to time, based upon
instructions from the Company (including any price, time or size
limits or other customary parameters or conditions the Company
may impose). The Company will pay Cowen a commission of up to
3.0% of the gross sales proceeds of any Common Stock sold through
Cowen under the Agreement, and also has provided Cowen with
customary indemnification rights.

The Company is not obligated to make any sales of Common Stock
under the Agreement. The offering of shares of Common Stock to
the Agreement will terminate upon the earlier of (i)the sale of
all Common Stock subject to the Agreement or (ii)termination of
the Agreement in accordance with its terms.

The foregoing description of the Agreement is not complete and is
qualified in its entirety by reference to the full text of the
Agreement, a copy of which is filed herewith as Exhibit 10.1 to
this Current Report on Form 8-K and is incorporated herein by
reference.

The shares of Common Stock being offered to the Agreement will be
offered and sold to the Companys shelf registration statement on
Form S-3 (File No.333-207876). On March27, 2017, the Company
filed a prospectus supplement relating to the ATM Offering with
the Securities and Exchange Commission.

The legal opinion of Cooley LLP relating to the shares of Common
Stock being offered to the Agreement is filed as Exhibit 5.1 to
this Current Report on Form 8-K.

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