Note 1 — Organization, Business Operation and Going Concern Consideration

Horizon Space Acquisition II Corp. (the “Company”) is a blank check company incorporated in the Cayman Islands on March 21, 2023 (“Inception”). The Company was formed for the purpose of effecting a merger, share exchange, asset acquisition, share purchase, reorganization, or similar business combination with one or more businesses (the “Business Combination”). The Company has selected December 31 as its fiscal year end.

As of March 31, 2026, the Company had not commenced any operations. For the period from March 21, 2023 (inception) through March 31, 2026, the Company’s efforts have been limited to organizational activities as well as activities related to the initial public offering, identifying a target company for a Business Combination and completing the SL Bio Business Combination (as defined below). The Company will not generate any operating revenues until after the completion of a Business Combination, at the earliest. The Company will generate non-operating income in the form of dividend and/or interest income from the proceeds derived from the IPO (as defined below) and private placement (“Private Placement,” see Note 4).

The Company’s founder and sponsor is Horizon Space Acquisition II Sponsor Corp., a Cayman Islands company (the “Sponsor”). The Company’s ability to commence operations is contingent upon obtaining adequate financial resources through IPO and the Private Placement.

On November 18, 2024, the Company consummated its initial public offering (the “IPO”) of 6,000,000 units (“Units”). Each unit consists of one ordinary share, and one right to receive one-tenth (1/10) of one ordinary share. Each ten rights entitle the holder thereof to receive one ordinary share upon the consummation of the Business Combination. The Units were sold at an offering price of $10.00 per Unit, generating total gross proceeds of $60,000,000. On November 19, 2024, the underwriter notified the Company of its exercise of the over-allotment option in full to purchase additional 900,000 Units of the Company (the “Over-Allotment Option”). As a result, on November 21, 2024, 900,000 Units were sold to the underwriter at an offering price of $10.00 per Option Unit (the “Option Units” and together with the Units, collectively, the “Public Units”), generating gross proceeds of $9,000,000. (refer to Note 3).

Simultaneously with the consummation of the IPO and the sale of the Units, the Company consummated the private placement (“Private Placement”) of 200,000 units (the “Initial Private Units”) to the Sponsor, at a price of $10.00 per Initial Private Unit, generating total proceeds of $2,000,000, which is described in Note 4. Simultaneously with the issuance and sale of the Option Units, the Company completed a private placement sale of additional 13,500 units (the “Additional Private Units” and together with the Initial Private Units, collectively, the “Private Units”) to the Sponsor at a purchase price of $10.00 per Additional Private Unit, generating gross proceeds of $135,000.

Transaction costs amounted to aggregated total of $1,844,819, consisting of $1,035,000 of underwriting commissions which was paid in cash at the closing date of the IPO, and upon the exercise of the overallotment option, $341,602 of the Representative Shares (discussed in the below), and $468,217 of other offering costs. At the IPO date, cash of $939,635 was held outside of the Trust Account (as defined below) and is available for the payment of accrued offering costs and for working capital purposes.

In conjunction with the IPO, the Company issued to the underwriter 210,000 ordinary shares for no consideration (the “Representative Shares”). The fair value of the Representative Shares accounted for as compensation under Accounting Standards Codification (“ASC”) 718, “Compensation – Stock Compensation” (“ASC 718”) is included in the offering costs. The fair value of the Representative Shares was estimated by using Black Scholes model as of the IPO date totaled $297,045. In connection with the exercise of the underwriter’s over-allotment option, the Company issued additional 31,500 Representative Shares to the underwriter with fair value of $44,557.

The Company’s initial Business Combination must occur with one or more target businesses that together have an aggregate fair market value of at least 80% of the assets held in the Trust Account (excluding interest income earned on the Trust Account that is released to the Company to pay taxes) at the time of the agreement to enter into the initial Business Combination. However, the Company will only complete such Business Combination if the post-transaction company owns or acquires 50% or more of the outstanding voting securities of the target or otherwise acquires a controlling interest in the target sufficient for it not to be required to register as an investment company under the Investment Company Act of 1940, as amended (the “Investment Company Act”). There is no assurance that the Company will be able to complete a Business Combination successfully.

Upon the closing of the IPO, management has agreed that the net proceeds of the IPO and the sale of the Private Units, $10.00 per unit will be placed into a U.S.-based Trust Account (“Trust Account”) maintained by Wilmington Trust, N.A., acting as trustee, and will be invested only in U.S. government treasury bills with a maturity of 185 days or less or in money market funds meeting certain conditions under Rule 2a-7 under the Investment Company Act which invest only in direct U.S. government treasury obligations. Except with respect to interest earned on the funds held in the Trust Account that may be released to pay the Company’s tax obligations and liquidation expenses up to $50,000, the proceeds from the IPO and the sale of the Private Units that are deposited in the Trust Account will not be released from the Trust Account until the earliest to occur of:(a) the completion of the initial Business Combination, (b) the redemption of any public shares properly submitted in connection with a shareholder vote to amend the Company’s memorandum and articles of association (i) to modify the substance or timing of the Company’s obligation to allow redemption in connection with the Business Combination or to redeem 100% of the Company’s public shares if the Company does not complete the Business Combination by June 18, 2026 (or up to February 18, 2027 if the Company extends the period of time to consummate the Business Combination by the full amount of time) as amended on February 13, 2026 pursuant to the extraordinary general meeting (the “Extension EGM”) or (ii) with respect to any other provision relating to shareholders’ rights or pre-initial Business Combination activity and (c) the redemption of the public shares if the Company is unable to complete the Business Combination by June 18, 2026 (or up to February 18, 2027 if the Company extends the period of time to consummate a Business Combination by the full amount of time) as amended on February 13, 2026 pursuant to the Extension EGM (the “Combination Period”), subject to applicable law. Although the Company will seek to have all vendors, including lenders for money borrowed, prospective target businesses or other entities the Company engages execute agreements with us waiving any right, title, interest or claim of any kind in or to any monies held in the Trust Account for the benefit of the Company’s public shareholders, the proceeds deposited in the Trust Account could become subject to the claims of the Company’s creditors, if any, which could have priority over the claims of the public shareholders.

The Company will provide its public shareholders with the opportunity to redeem all or a portion of their public shares upon the completion of the Business Combination either (i) in connection with a shareholder meeting called to approve the Business Combination or (ii) by means of a tender offer.

The ordinary shares subject to redemption accredited to the redemption value and classified as temporary equity upon the completion of the IPO, in accordance with Financial Accounting Standard Board’s (FASB) Accounting Standards Codification (“ASC”) Topic 480“Distinguishing Liabilities from Equity.” In such case, the Company has determined that the Company will proceed with a Business Combination if the Company has net tangible assets of at least $5,000,001 upon such consummation of a Business Combination and, if the Company seeks shareholder approval, a majority of the issued and outstanding shares votes are voted in favor of the Business Combination. If the Company cannot complete a Business Combination by June 18, 2026 (or up to February 18, 2027 if the Company extends the period of time to consummate a Business Combination by the full amount of time) as amended on February 13, 2026 pursuant to the Extension EGM, unless the Company extends such period pursuant to its amended and restated memorandum and articles of association, the Company will: (i) cease all operations except for the purpose of winding up, (ii) as promptly as reasonably possible but not more than ten business days thereafter, redeem the public shares, at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest (which interest shall be net of income taxes payable, and less up to $50,000 of interest to pay liquidation expenses) divided by the number of then outstanding public shares, which redemption will completely extinguish public shareholders’ rights as shareholders (including the right to receive further liquidation distributions, if any), subject to applicable law, and (iii) as promptly as reasonably possible following such redemption, subject to the approval of the Company’s remaining shareholders and Board of Directors, liquidate and dissolve, subject in each case to the Company’s obligations under Cayman Islands law to provide for claims of creditors and the requirements of other applicable law. There will be no redemption rights or liquidating distributions with respect to public rights or private rights. The rights will expire worthless if the Company fails to complete a Business Combination by June 18, 2026 (or up to February 18, 2027 if the Company extends the period of time to consummate a Business Combination by the full amount of time) as amended on February 13, 2026 pursuant to the Extension EGM.

Extension Deposit and Notes

Pursuant to the terms of the Company’s memorandum and articles of association, in order to extend the time available for the Company to consummate its initial Business Combination, the Sponsor or designees, must deposit into the Trust Account for each three months extension, $690,000 as the underwriter’s over-allotment option had been exercised in full ($0.10 per share in either case), up to an aggregate of $1,380,000, on or prior to the date of the applicable deadline. In November 2025, $690,000 was deposited into the Trust Account for the Company’s public shareholders, which extended the deadline to consummate a Business Combination to February 18, 2026.

Pursuant to the amendment to the amended and restated memorandum and articles of association approved in the extraordinary general meeting held on February 13, 2026 (the “Charter Amendment”) of the Company, the Company has until February 18, 2026 to complete its initial business combination. However, the Company may extend the period of time to consummate a business combination up to twelve times, each by an additional one-month extension, up to February 18, 2027, subject to the Sponsor and/or its designee, depositing the lesser of (i) $50,000 for all remaining public shares and (ii) $0.033 for each remaining public share (the “Extension Fee”) into the Trust Account.

For the three months ended March 31, 2026, an aggregate total of $100,000 was deposited into the Trust Account by William Wang, the Chief Executive Officer of SL BIO, on behalf of the Company’s public shareholders, to extend the deadline for the Company to consummate its initial Business Combination to April 18, 2026. In connection with such extensions, the Company issued two unsecured promissory notes (see Note 5) to William Wang, each with a principal amount of $50,000, on February 18, 2026 and March 17, 2026, respectively.

On April 18, 2026 and May 14, 2026, an aggregate total of $100,000, consisting of two installments of $50,000 each, was deposited into the Trust Account on behalf of the Company’s public shareholders to further extend the deadline for the Company to consummate its initial Business Combination to June 18, 2026. Of the aggregate amount deposited, $50,000 was funded by the Sponsor and $50,000 was funded by William Wang. In connection with such extensions, the Company issued unsecured promissory notes with a principal amount of $50,000 each on April 18, 2026 and May 18, 2026 to the Sponsor and William Wang, respectively.

Business Combination

On May 9, 2025, the Company entered into a business combination agreement (the “Business Combination Agreement”) with SL Science Holding Limited, a Cayman Islands exempted company (“PubCo”), CW Mega Limited, a Cayman Islands exempted company and a wholly-owned subsidiary of PubCo (“Merger Sub I”), WW Century Limited, a Cayman Islands exempted company and a wholly-owned subsidiary of PubCo (“Merger Sub II”), and SL Bio Ltd., a Cayman Islands exempted company limited by shares (“SL Bio”), pursuant to which, among other things, (i) Merger Sub I will merge with and into the Company, with the Company as the surviving entity and a wholly-owned subsidiary of PubCo (the “First Merger”), and (ii) following the First Merger, Merger Sub II will merge with and into SL Bio, with SL Bio as the surviving entity and a wholly-owned subsidiary of PubCo (the “Second Merger,” and together with the First Merger and the other transactions contemplated by the Business Combination Agreement, the “SL Bio Business Combination”). In connection with the SL Bio Business Combination, PubCo filed with the SEC a registration statement on Form F-4 (File No. 333-292214), which was declared effective on January 13, 2026 (as amended and supplemented, the “Form F-4”), and the Company filed a definitive proxy statement (as amended and supplemented, the “Proxy Statement”) for the solicitation of proxies in connection with an extraordinary general meeting of the Company’s shareholders on January 13, 2026.

On May 9, 2025, the Company entered into a Business Combination Agreement with SL Science Holding Limited (“PubCo”), its wholly owned subsidiaries, and SL BIO Ltd., pursuant to which a series of mergers will be effected resulting in the Company and SL BIO becoming wholly owned subsidiaries of PubCo, and the Company’s shareholders receiving PubCo ordinary shares. In connection with the Business Combination, on March 24, 2026, PubCo entered into subscription agreements with certain investors for a private placement (the “PIPE Financing”) of 780,000 units at $10.00 per unit for aggregate gross proceeds of $7,800,000. Each unit consists of one PubCo ordinary share and one preferred share, with each preferred share convertible into one-third of one PubCo ordinary share six months following the closing of the Business Combination.

Going Concern Consideration

As of March 31, 2026, the Company had cash of $9,586 and working capital deficit of $1,784,554, excluding $37,482,848 payables due to redeeming shareholders to be paid out from the Trust Account. The Company has incurred and expects to continue to incur significant professional costs to remain as a publicly traded company and to incur significant transaction costs in pursuit of the consummation of a Business Combination.

The Company expects to continue to incur significant professional costs to remain as a publicly traded company and to incur significant transaction costs in pursuit of the consummation of a Business Combination. The Company may need to obtain additional financing either to complete its Business Combination or because it becomes obligated to redeem a significant number of public shares upon consummation of its Business Combination, in which case, subject to compliance with applicable securities laws, the Company may issue additional securities or incur debt prior to or in connection with such Business Combination.

In connection with the Company’s assessment of going concern considerations in accordance with ASC Subtopic 205-40, Presentation of Financial Statements - Going Concern, management has determined that these conditions raise substantial doubt about the Company’s ability to continue as a going concern. Management’s plan in addressing this uncertainty is through the Working Capital Loans, as defined below (see Note 6). Accordingly, the Company may not be able to obtain additional financing. If the Company is unable to raise additional capital, it may be required to take additional measures to conserve liquidity, which could include, but not necessarily be limited to, curtailing operations, suspending the pursuit of a potential transaction, and reducing overhead expenses. The Company cannot provide any assurance that new financing will be available to it on commercially acceptable terms, if at all.

The Company has incurred and expects to continue to incur significant costs in pursuit of its financing and acquisition plans. The Company currently has no commitments in place to receive such financing and there is no assurance that the Company’s plans to raise capital will be successful. In addition, if the Company is unable to complete a Business Combination by June 18, 2026 (or up to February 18, 2027 if fully extended), unless further extended, the Company’s board of directors would proceed to commence a voluntary liquidation and thereby a formal dissolution of the Company. There is no assurance that the Company’s plans to consummate a Business Combination will be successful within the Combination Period. As a result, management has determined that such additional condition also raise substantial doubt about the Company’s ability to continue as a going concern for a period within one year after the date that the accompanying unaudited condensed financial statements are issued. The unaudited condensed financial statements of the Company do not include any adjustments that might result from the outcome of this uncertainty.

Risks and Uncertainties

As a result of the ongoing Russia/Ukraine, Hamas/Israel conflicts and/or other future global conflicts, the Company’s ability to consummate a Business Combination, or the operations of a target business with which the Company ultimately consummates a Business Combination, may be materially and adversely affected. In addition, the Company’s ability to consummate a transaction may be dependent on the ability to raise equity and debt financing which may be impacted by these events, including as a result of increased market volatility, or decreased market liquidity in third-party financing being unavailable on terms acceptable to the Company or at all. The impact of this action and potential future sanctions on the world economy and the specific impact on the Company’s financial position, results of operations or ability to consummate a Business Combination are not yet determinable. The unaudited condensed financial statements of the Company do not include any adjustments that might result from the outcome of this uncertainty.