ADAPTIMMUNE THERAPEUTICS PLC (NASDAQ:ADAP) Files An 8-K Entry into a Material Definitive Agreement

Item 1.01 Entry into a Material Definitive Agreement.

On March22, 2017, Adaptimmune Therapeutics plc (the Company)
entered into an underwriting agreement (the Underwriting
Agreement) with Citigroup Global Markets Inc., Cowen and Company,
LLC, and Leerink Partners LLC, as representatives of the several
underwriters named therein (collectively, the Underwriters), to
which the Company agreed to issue and sell an aggregate of
14,300,000 of its American Depositary Shares (ADSs) to the
Underwriters (the Offering). Each ADS represents six ordinary
shares of the Company. The ADSs will be sold at a public offering
price of $4.20 per ADS. The Company expects to receive aggregate
net proceeds from the sale of the ADSs of approximately $56.3
million, after deducting underwriting fees and commissions and
estimated offering expenses. to the Underwriting Agreement, the
Company also granted the Underwriters a 30-day option to purchase
up to 2,145,000 additional ADSs at the public offering price. The
Offering is expected to close on March27, 2017.

The Underwriting Agreement contains 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, other obligations of the parties and
termination provisions. The representations, warranties and
covenants contained in the Underwriting Agreement 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.
The Company and all of the Companys directors and executive
officers also agreed to not sell or transfer any ADSs of the
Company for 90 days after March22, 2017 without first obtaining
the consent of Citigroup Global Markets Inc., Cowen and Company,
LLC and Leerink Partners LLC.

The Offering is being made to the Companys effective shelf
registration statement on FormS-3 (Registration No.333-212713),
including the prospectus contained therein, effective
September12, 2016, as the same has been amended and/or
supplemented from time to time.

A copy of the Underwriting Agreement is attached hereto as
Exhibit1.1 and is incorporated herein by reference. The foregoing
description of the terms of the Underwriting Agreement is
qualified in its entirety by reference to such exhibit. A copy of
the opinion of Mayer Brown International LLP relating to the
legality of the issuance and the ordinary shares underlying the
ADSs in this offering is attached as Exhibit5.1 hereto.

Item 8.01. Other Events.

On March21, 2017, the Company issued a press release announcing
the commencement of the Offering and issued a subsequent press
release on March22, 2017 announcing the pricing of the Offering.
Copies of these press releases are attached hereto as Exhibits
99.1 and 99.2 hereto, respectively, and are incorporated by
reference herein.

About ADAPTIMMUNE THERAPEUTICS PLC (NASDAQ:ADAP)

Adaptimmune Therapeutics plc is a clinical-stage biopharmaceutical company. The Company is focused on cancer immunotherapy products based on its T-cell receptor (TCR) platform. The Company has developed a platform that enables it to identify cancer targets in the form of peptides, which are short sequences of amino acids, find and genetically engineer TCRs, and produce TCR therapeutic candidates for administration to patients. The Company engineers TCRs to increase their affinity to cancer-specific peptides, including its lead target peptides, NY-ESO-1 and MAGE-A10, in order to target and then destroy cancer cells in patients. The Company’s TCR therapeutic candidates are able to target intracellular, as well as extracellular cancer antigens. The TCRs consist of approximately two associated protein chains: the alpha and beta chains. Each of the chains has approximately two regions: a variable region and a constant region.

ADAPTIMMUNE THERAPEUTICS PLC (NASDAQ:ADAP) Recent Trading Information

ADAPTIMMUNE THERAPEUTICS PLC (NASDAQ:ADAP) closed its last trading session up +0.01 at 4.30 with 2,160,883 shares trading hands.