Akari Therapeutics Plc

As filed with the Securities and Exchange Commission on January 23, 2026

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORMS-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

(Exact name of registrant as specified in its charter)

401 East Jackson St**, Suite 3300**

Tampa, FL 33602

(929) 274-7510

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Abizer Gaslightwala

President and Chief Executive Officer

401 East Jackson St**, Suite 3300 **

Tampa, FL 33602

(929) 274-7510

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Gary Emmanuel, Esq.

Win Rutherfurd, Esq.

Greenberg Traurig, LLP

One Vanderbilt Avenue

New York, NY 10017

Tel: (212) 801-9200

Approximate date of commencement of proposed sale to the public: From time to time after this Registration Statement becomes effective.

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box. ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended, or until this registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

The information in this preliminary prospectus is not complete and may be changed. The selling stockholders may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

Akari Therapeutics, PLC

34,680,906 American Depositary Shares Representing 69,361,812,000 Ordinary Shares

This prospectus relates to the offer and sale, by the selling stockholders identified in this prospectus, or the selling stockholders, from time to time of up to 34,680,906 American Depositary Shares, or ADSs, each representing 2,000 ordinary shares, $0.000000005 nominal value per share, or the Ordinary Shares, consisting of: (i) 12,607,487 ADSs representing 25,214,974,000 Ordinary Shares issuable upon the exercise of unregistered Series G Warrants issued in a concurrent private placement conducted together with a registered direct offering in December 2025, or the Registered Direct Offering, (ii) 2,563,713 ADSs representing 5,127,426,000 Ordinary Shares issuable upon exercise of unregistered pre-funded warrants, or the Pre-Funded Warrants, issued in a concurrent private placement, or the Private Placement and together with the Registered Direct Offering, the December 2025 Offerings, (iii) 9,502,703 ADSs representing 19,005,406,000 Ordinary Shares issuable upon exercise of Pre-Funded Warrants issued in a privately negotiated note cancellation and exchange, or the Exchange, (iv) 9,502,703 ADSs representing 19,005,406,000 Ordinary Shares issuable upon exercise of unregistered note exchange warrants, or the Note Exchange Warrants, issued in the Exchange, and (v) 504,300 ADSs representing 1,008,600,000 Ordinary Shares issuable upon exercise of placement agent warrants issued in connection with the Offerings, or the Placement Agent Warrants, and collectively with the foregoing Series G Warrants, Pre-Funded Warrants and Note Exchange Warrants, the Warrants.

We agreed to call a meeting of our shareholders, the Special Meeting, for the purpose of obtaining, among other things, shareholder approval, the Shareholder Approval, of the issuance of the Ordinary Shares represented by the ADSs underlying the Warrants within seventy-five (75) days of the closing date of the December 2025 Offerings and the Exchange. If Shareholder Approval is not obtained at the Special Meeting, we will call a meeting every forty (40) days thereafter to seek Shareholder Approval until Shareholder Approval is obtained or the Warrants are no longer outstanding. The exercisability of the Warrants described below is conditioned upon Shareholder Approval and, until such approval is obtained, the Warrants may not be exercised for ADSs representing Ordinary Shares.

We are not selling any ADSs being offered by this prospectus and will not receive any of the proceeds from the sale of such shares by the selling stockholders. All net proceeds from the sale of the ADSs covered by this prospectus will go to the Selling Stockholders. However, we may receive the proceeds from any exercise of Warrants if the holders do not exercise the Warrants on a cashless basis. See “Use of Proceeds.”

The selling stockholders may sell or otherwise dispose of the ADSs representing Ordinary Shares described in this prospectus in different ways and at varying prices. See “Plan of Distribution” for more information about how the selling stockholders may sell or otherwise dispose of ADSs representing Ordinary Shares being registered pursuant to the registration statement of which this prospectus forms a part.

We will pay the expenses of registering the offer and sale of the ADSs representing Ordinary Shares under the Securities Act of 1933, as amended, or the Securities Act, to which this prospectus relates by the selling stockholders, including legal and accounting fees. See “Plan of Distribution”.

Our ADSs are listed on the Nasdaq Capital Market under the symbol “AKTX.” On January 22, 2026, the closing price of our ADSs was $0.268.

INVESTING IN OUR SECURITIES INVOLVES SIGNIFICANT RISKS THAT ARE DESCRIBED IN THE “RISK FACTORS” SECTION BEGINNING ON PAGE 6 OF THIS PROSPECTUS

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the securities to be issued under this prospectus or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is January , 2026.

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