As filed with the Securities and Exchange Commission on May 26, 2021.

Registration No. 333-255393

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

Amendment No. 3

to

FORM S-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

CENTESSA PHARMACEUTICALS PLC

(Exact Name of Registrant as Specified in Its Charter)

Centessa Pharmaceuticals plc

3rd Floor, 1 Ashley Rd,

Altrincham, Cheshire,

United Kingdom, WA14 2DT

+44 7391 789784

(Address, Including Zip Code, and Telephone Number, Including Area Code, of Registrant’s Principal Executive Offices)

Saurabh Saha

Chief Executive Officer

Centessa Pharmaceuticals, Inc.

5 Walnut Grove Drive,

Suite 120 Horsham, PA 19044

+1 (267) 609-7550

+1 (617)-468-5770

(Name, Address, Including Zip Code, and Telephone Number, Including Area Code, of Agent For Service)

  Copies to:

+44 7391 789784

Approximate date of commencement of proposed sale to the public:

As soon as practicable after the effective date of this registration statement.

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, as amended, 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 13(a) of the Exchange 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 or until this registration statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.

EXPLANATORY NOTE

This Amendment No. 3 to the Registration Statement on Form S-1 (File No. 333-255393), or the Registration Statement, is filed solely to amend Item 16 of Part II thereof and to file Exhibit 1.1 and Exhibit 5.1 thereto. Accordingly, this Amendment No. 3 consists only of the facing page, this explanatory note, Part II of the Registration Statement, the signature page to the Registration Statement, and the exhibits filed herewith. This Amendment No. 3 does not modify any provision of the preliminary prospectus contained in Part I of the Registration Statement. Accordingly, the preliminary prospectus has been omitted.

PART II

Information Not Required in Prospectus

The following table sets forth the fees and expenses, other than underwriting discounts and commissions, which are expected to be incurred in connection with our sale of ADSs in this offering. With the exception of the registration fee payable to the SEC, the Nasdaq listing fee and the filing fee payable to FINRA, all amounts are estimates.

Subject to the Companies Act, members of the registrant’s board of directors and its officers (excluding auditors) have the benefit of the following indemnification provisions in the registrant’s Articles of Association:

Current and former members of the registrant’s board of directors or officers shall be reimbursed for:

(i) all costs, charges, losses, expenses and liabilities sustained or incurred in relation to his or her actual or purported execution of his or her duties in relation to the registrant, including any liability incurred in defending any criminal or civil proceedings; and

(ii) expenses incurred or to be incurred in defending any criminal or civil proceedings, in an investigation by a regulatory authority or against a proposed action to be taken by a regulatory authority, or in connection with any application for relief under the statutes of the United Kingdom and any other statutes that concern and affect the registrant as a company, or collectively the Statutes, arising in relation to the registrant or an associated company, by virtue of the actual or purposed execution of the duties of his or her office or the exercise of his or her powers.

In the case of current or former members of the registrant’s board of directors, there shall be no entitlement to reimbursement as referred to above for (i) any liability incurred to the registrant or any associated company, (ii) the payment of a fine imposed in any criminal proceeding or a penalty imposed by a regulatory authority for non-compliance with any requirement of a regulatory nature, (iii) the defense of any criminal proceeding if the member of the registrant’s board of directors is convicted, (iv) the defense of any civil proceeding brought by the registrant or an associated company in which judgment is given against the director and (v) any application for relief under the statutes of the United Kingdom and any other statutes that concern and affect the registrant as a company in which the court refuses to grant relief to the director.

In addition, members of the registrant’s board of directors and its officers who have received payment from the registrant under these indemnification provisions must repay the amount they received in accordance with the Statutes or in any other circumstances that the registrant may prescribe or where the registrant has reserved the right to require repayment.

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The underwriting agreement the registrant will enter into in connection with the offering of ADSs being registered hereby provides that the underwriters will indemnify, under certain conditions, the registrant’s board of directors and its officers against certain liabilities arising in connection with this offering.

In the three years preceding the filing of this Registration Statement, we have issued the following securities that were not registered under the Securities Act:

In October 2020 we issued a single subscriber share (being one Ordinary Share of £1) issued to an individual associated with Medicxi. On November 27, 2020, the one Ordinary Share of £1 held by an individual associated with Medicxi was sub-divided into 500 Ordinary Shares of £0.002 each; and Centessa issued 6,747,500 Ordinary Shares to individuals associated with Medicxi and on 2 December 2020, Centessa issued 752,000 further Ordinary Shares to the Index Foundation. Each of the 7,500,000 Ordinary Shares were redesignated as A Ordinary Shares in connection with the closing of the Crossover Investment (as defined below) on January 29, 2021 and 4,450,000 A Ordinary Shares were acquired for nominal value and cancelled by Centessa.

On December 31, 2020 in the case of PearlRiver Bio (as amended from time to time) and January 23, 2021 in the case of all other Centessa Subsidiaries (other than Palladio Biosciences), all shareholders of each of the Centessa Subsidiaries (other than Palladio Biosciences) exchanged the shares held by them in the relevant Centessa Subsidiary for newly issued B ordinary shares of Centessa Pharmaceuticals Limited in exchange for 100% of the equity of each applicable entity.

On January 31, 2021 Palladio Biosciences entered into an agreement and plan of reorganization (the Merger Agreement) with Centessa UPM Merger Sub, Inc. (a subsidiary of Centessa incorporated in Delaware for the purposes of merging with Palladio Biosciences). Pursuant to the Merger Agreement, UPM Merger Sub, Inc. merged with and into Palladio Biosciences as the surviving corporation with the shareholders of Palladio receiving B ordinary shares of Centessa and certain Contingent Value Rights.

Between December 31, 2020 and January 31, 2021, we issued 44,635,383 B Ordinary Shares and 502,602 A Ordinary Shares to the former equity holders of the Centessa Subsidiaries in connection with certain reorganization transactions. For more Information, see “Share Capital Reorganization and Re-registration.”

In January 2021, we issued 22,272,721 Series A preferred shares to 16 investors for an aggregate subscription price of $245 million.

The sales of securities described above were deemed to be exempt from registration pursuant to Section 4(a)(2) of the Securities Act, including Regulation D and Rule 506 promulgated thereunder, as transactions by an issuer not involving a public offering, or pursuant to Regulation S promulgated under the Securities Act in that offers, sales and issuances were not made to persons in the United States and no directed selling efforts were made in the United States. All of the purchasers in these transactions represented to us in connection with their purchase that they were acquiring the securities for investment and not distribution, that they could bear the risks of the investment and could hold the securities for an indefinite period of time. Such purchasers received written disclosures that the securities had not been registered under the Securities Act and that any resale must be made pursuant to a registration or an available exemption from such registration. All of the foregoing securities are deemed restricted securities for the purposes of the Securities Act.

From our inception to the date of the prospectus that forms a part of this registration statement, we issued share options to subscribe for an aggregate of 11,126,809 ordinary shares, with exercise prices ranging from $5.84 to $9.42 per ordinary share, to employees and directors.

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From our inception to the date of the prospectus that forms a part of this registration statement, we issued              ordinary shares to individuals upon exercise of options for an aggregate subscription price of £            .

The issuances of the securities described above were deemed to be exempt from registration pursuant to Section 4(a)(2) of the Securities Act or Rule 701 promulgated under the Securities Act as transactions pursuant to compensatory benefit plans, or pursuant to Regulation S promulgated under the Securities Act in that offers, sales and issuances were not made to persons in the United States and no directed selling efforts were made in the United States. The ordinary shares issued upon the exercise of options are deemed to be restricted securities for purposes of the Securities Act.

All certificates representing the securities issued in the transactions described in this Item 15 included appropriate legends setting forth that the securities had not been offered or sold pursuant to a registration statement and describing the applicable restrictions on transfer of the securities. There were no underwriters employed in connection with any of the transactions set forth in this Item 15.

On December 29, 2020, Centessa entered into a convertible loan agreement with Medicxi Growth I LP and Medicxi Growth Co-Invest I LP (collectively Medicxi Growth), whereby the Company issued $5.0 million of unsecured convertible term notes to Medicxi Growth (the Convertible Notes).The Convertible Notes converted into an aggregate 568,181 Series A Shares at a subscription price of $8.799999964 in connection with the closing of the Crossover Investment on January 29, 2021.

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Schedules have been omitted because the information required to be set forth therein is not applicable or is shown in the financial statements or notes thereto.

Insofar as indemnification for liabilities arising under the Securities Act of 1933, as amended, or the Act, may be permitted to directors, officers and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the Registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Act and is therefore unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a director, officer or controlling person of the Registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Act and will be governed by the final adjudication of such issue.

The Registrant hereby undertakes that:

(a) The Registrant will provide to the underwriter at the closing as specified in the underwriting agreement, certificates in such denominations and registered in such names as required by the underwriter to permit prompt delivery to each purchaser.

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(b) For purposes of determining any liability under the Securities Act of 1933, as amended, the information omitted from a form of prospectus filed as part of this registration statement in reliance upon Rule 430A and contained in the form of prospectus filed by the Registrant pursuant to Rule 424(b)(1) or (4) or 497(h) under the Securities Act of 1933, as amended, shall be deemed to be part of this registration statement as of the time it was declared effective.

(c) For the purpose of determining any liability under the Securities Act of 1933, as amended, each post-effective amendment that contains a form of prospectus shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant has duly caused this registration statement on Form S-1 to be signed on its behalf by the undersigned, thereunto duly authorized, under the laws and regulations of England and Wales, on May 26, 2021.

SIGNATURES

Pursuant to the requirements of the Securities Act, this registration statement has been signed by the following persons in the capacities and on the dates indicated.

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