西北生物疗法美股招股说明书(2026-07-31版)

40,325,000 Shares of Common Stock On July 29, 2026, Northwest Biotherapeutics,Inc. (the “Company”) entered into a $4.9 million convertible promissory notefinancing (the “Note”) with YA II PN, Ltd., per the Form 8-K filed with the SEC onJuly 31, 2026. The Note transaction involvespotential share issuances related to the conversion of the Note principal amount, which shares are being registered pursuant to thisprospectus supplement. The Company assumes an offering of 30,625,000 shares a price per share of $0.16 (the market closing price onJuly 29, 2026) with the understanding that the number of shares to be issued and their price may be higher or lower over time. TheCompany is also registering 9,700,000 shares issuable upon exercise of $2 million of warrants at a price per share of $0.205. Our common stock, par value $0.001 per share (“Common Stock”) is traded on the OTCQB tier of the OTC Markets under Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on pageS-2 of this prospectussupplement and on page3 of the accompanying prospectus and the documents incorporated by reference herein for adiscussion of certain risks that should be considered in connection with an investment in our securities. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved ofthese securities or determined whether this prospectus supplement or the accompanying prospectus is truthful or complete.Any representation to the contrary is a criminal offense. Per ShareTotalOffering price per share of Common Stock$0.16$4,900,000Proceeds to us after OID, a facility commitment fee and expenses$4,655,000 The date of this prospectus supplement is July 31, 2026. TABLE OF CONTENTS Prospectus Supplement About This Prospectus SupplementS–iiCautionary Statement Regarding Forward-Looking StatementsS–ivProspectus Supplement SummaryS–1Risk FactorsS–2Use of ProceedsS–2Dividend PolicyS–2DilutionS–2Description of SecuritiesS–3ExpertsS–5Where You Can Find More InformationS–5Incorporation of Certain Information by ReferenceS–5 Prospectus ABOUT THIS PROSPECTUS1ABOUT NORTHWEST BIOTHERAPEUTICS,INC.2RISK FACTORS3THE OFFERING4SPECIAL NOTE REGARDING FORWARD-LOOKING INFORMATION5USE OF PROCEEDS7DILUTION8DESCRIPTION OF COMMON STOCK9CERTAIN ANTI-TAKEOVER AND INDEMNIFICATION PROVISIONS OF OUR CERTIFICATE OFINCORPORATION AND BY-LAWS AND DELAWARE LAW10PLAN OF DISTRIBUTION12EXPERTS13VALIDITY OF THE SECURITIES13WHERE YOU CAN FIND MORE INFORMATION14INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE15 ABOUT THIS PROSPECTUS SUPPLEMENT On October24, 2025, we filed with the Securities and Exchange Commission, or “SEC,” a registration statement on FormS-3 (File No.333-291044). On April 16, 2026 we filed a Post-Effective Amendment to convert that registration statement from Form S-3to Form S-1. Under this shelf registration process, we may, from time to time, sell up to $250 million in the aggregate of CommonStock, preferred stock, depositary shares, warrants, various series of debt securities, share purchase contracts, share purchase units, andwarrants to purchase any of such securities, either individually or in units. Under this shelf registration process, we are offering to sell Common Stock using this prospectus supplement and theaccompanying prospectus. In this prospectus supplement, we provide you with specific information about the securities that we areselling in this offering. Both this prospectus supplement and the accompanying prospectus include important information about us, oursecurities being offered and other information you should know before investing. This prospectus supplement also adds, updates andchanges information contained in the accompanying prospectus. You should read this prospectus supplement and the accompanyingprospectus as well as additional information described under “Incorporation of Certain Information by Reference” on pageS-5 of thisprospectus supplement before investing in our securities. This prospectus supplement describes the specific terms of an offering of our securities and also adds to and updatesinformation contained in the accompanying prospectus and the documents incorporated by reference into this prospectus supplementand in the accompanying prospectus. The second part, the accompanying prospectus, provides more general information. If theinformation in this prospectus supplement is inconsistent with the accompanying prospectus or any document incorporated byreference herein or therein filed prior to the date of this prospectus supplement, you should rely on the information in this prospectussupplement. In making your investment decision, you should rely only on the information contained or incorporated by reference in thisprospectus supplement and the accompanying prospectus and any relevant free writing prospectus. We have not authorized anyone toprovide you with any other information. If you receive any information not author