13G Filing: Woodford Investment Management and Northwest Biotherapeutics Inc (NWBO)

SCHEDULE 13G

CUSIP NO. 66737P600

EXHIBIT 1

JOINT FILING AGREEMENT

In accordance with
Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf
of each of them of a statement on Schedule 13G (including amendments thereto) with respect to the Common Stock of the Issuer and
further agree that this Joint Filing Agreement be included as an Exhibit to such joint filings.

Dated: September 11, 2017

	WOODFORD INVESTMENT MANAGEMENT LTD
	By:	/s/ Chris Martin
		Name:	Chris Martin
		Title:	Head of Compliance and Authorized Signatory
	/s/ Neil Woodford
	Neil Woodford

IDENTIFICATION AND CLASSIFICATION OF
MEMBERS OF THE GROUP

The Group filing this Schedule 13G is comprised of Woodford
Investment Management Ltd and Neil Woodford, its Head of Investment.

Item 3 Classification:

Woodford Investment Management Ltd:  A non-U.S. institution
in accordance with §240.13d-1(b)(1)(ii)(J).

Neil Woodford: A parent holding company or control person in
accordance with § 240.13d-1(b)(1)(ii)(G).

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