Ikena Oncology Inc美股招股说明书(2025-06-11版)

To the Stockholders of Ikena Oncology, Inc., Ikena Oncology, Inc., a Delaware corporation (“Ikena”), and Inmagene Biopharmaceuticals, an exemptedcompany with limited liability incorporated and existing under the laws of the Cayman Islands (“Inmagene”), enteredinto an Agreement and Plan of Merger (the “Merger Agreement”) on December23, 2024, pursuant to which, amongother matters, Insight Merger Sub I, a direct, wholly owned subsidiary of Ikena (“Merger Sub I”), will merge with andinto Inmagene, with Inmagene surviving as a wholly owned subsidiary of Ikena (such transaction, the “First Merger”),and immediately after the First Merger, the surviving entity will merge with and into Insight Merger Sub II, a direct,wholly owned subsidiary of Ikena (“Merger Sub II”), with Merger Sub II surviving as a wholly owned subsidiary ofIkena (such transaction, the “Second Merger” and, collectively with the First Merger, as appropriate, the “Merger”).The surviving corporation following the Merger is referred to herein as the “combined company.” At the effective time of the First Merger (the “first effective time”), (i) each ordinary share of Inmagene, par value$0.00005 per share (“Inmagene ordinary shares”), and each preferred share of Inmagene, par value $0.00005 per share(“Inmagene preferred shares” and, together with the Inmagene ordinary shares, “Inmagene shares”), (other than sharesheld as treasury shares and shares with respect to which the holder thereof has validly exercised and not effectivelywithdrawn or lost such holder’s right to dissent from the Merger in accordance with Section238 of the Companies Act(As Revised) of the Cayman Islands (the “CICA”) (“Dissenting Shares”)) will be converted into the right to receive anumber of shares of common stock of Ikena, par value $0.001per share (“Ikena common stock”), calculated byreference to the Exchange Ratio (as defined and described in more detail in the section titled “The Merger Agreement—Exchange Ratio” beginning on page 196 of the accompanying proxy statement/prospectus) and (ii) each thenoutstanding and unexercised option to purchase Inmagene ordinary shares will be converted into an option to purchaseshares of Ikena common stock, with the number of shares and exercise price adjusted to reflect the Exchange Ratio.The Exchange Ratio formula is derived based upon an Inmagene fixed valuation of $150 million and an Ikena equityvalue of $120 million, and the final Exchange Ratio is subject to adjustment prior to the first effective time based upon,among other things, Ikena’s net cash (as defined and described in more detail in the section titled “The MergerAgreement—Determinationof Ikena’s Net Cash”beginning on page 197 of the accompanying proxystatement/prospectus). As a result, Ikena stockholders could own more, and Inmagene securityholders could own less,or vice versa, of the combined company. Based on Ikena’s and Inmagene’s capitalization as of April 30, 2025, andassuming Ikena’s net cash is $100million, the Exchange Ratio was estimated to be equal to 0.003177 shares of Ikenacommon stock for each Inmagene share, which estimated Exchange Ratio gives effect to an assumed reverse stock splitratio of 1:12 as described elsewhere in this proxy statement/prospectus. The following table illustrates a range of Exchange Ratios (including a high and a low range) at various figures ofIkena net cash, which estimated Exchange Ratios gives effect to an assumed reverse stock split ratio of 1:12, and doesnot give effect to any other Ikena Legacy Proceeds (as defined in the Merger Agreement): Each share of Ikena common stock issued and outstanding at the time of the Merger will remain issued andoutstanding, and, subject to the proposed reverse stock split and any acceleration of equity awards provided for inconnection with the Merger, will be unaffected by the Merger. TABLE OF CONTENTS Prior to the closing of the Merger, Ikena’s board of directors (the “Ikena board”) will adopt appropriateresolutions and take all other actions necessary and appropriate to provide that the vesting of each unexpired,unexercised and unvested option to purchase Ikena common stock (each, an “Ikena option”) will be accelerated infull effective as of immediately prior to the first effective time, contingent on the occurrence of the closing, and eachunexpired, unexercised and fully vested Ikena option (i) granted under the Ikena 2021 Stock Option and IncentivePlan (each, a “2021 Ikena option”) will automatically be cancelled and extinguished as of the first effective timeand, in exchange therefor, each former holder of any such 2021 Ikena option will have the right to receive fromIkena or the combined company a number of shares of Ikena common stock equal to the Option Value (as definedbelow), and (ii) granted under the Ikena 2016 Stock Incentive Plan (each, a “2016 Ikena option”) will remainoutstanding pursuant to its terms, unless the holder of such 2016 Ikena option will have agreed for such 2016 Ik