SL Science Holding Ltd

On June 12, 2026 (the “Closing Date”), SL Science Holding Limited, a Cayman Islands exempted company (“SLBT,” “SL Science” or the “Company”), consummated the previously announced business combination (the “Business Combination”) pursuant to the Business Combination Agreement, dated May 9, 2025 (as may be amended, supplemented, or otherwise modified from time to time, the “Business Combination Agreement”), by and among SLBT, Horizon Space Acquisition II Corp., a Cayman Islands exempted company limited by shares (“HSPT”), CW Mega Limited, a Cayman Islands exempted company limited by shares and a wholly-owned subsidiary of SLBT (“Merger Sub I”), WW Century Limited, a Cayman Islands exempted company limited by shares and a wholly-owned subsidiary of SLBT (“Merger Sub II”), and SL BIO Ltd., a Cayman Islands exempted company limited by shares (“SL Bio”).

As a result of the Business Combination, (i) Merger Sub I merged with and into HSPT, with HSPT as the surviving entity and a wholly-owned subsidiary of SLBT (the “First Merger”), and (ii) following the First Merger, Merger Sub II merged with and into SL Bio, with SL Bio as the surviving entity and a wholly-owned subsidiary of SLBT (the “Second Merger”). Upon the consummation of the Business Combination, each of HSPT and SL Bio became a subsidiary of SLBT, and HSPT’s shareholders and SL Bio’s shareholders received ordinary shares of par value of $0.00001 each of SLBT (“PubCo Ordinary Shares” or “Ordinary Shares”).

Pursuant to the Business Combination Agreement, (i) immediately prior to the First Merger Effective Time (as defined in the Business Combination Agreement), (a) each Acquiror Unit (as defined in the Business Combination Agreement) issued and outstanding immediately prior to the First Merger Effective Time were automatically detached and the holder thereof were deemed to hold one Acquiror Ordinary Share (as defined in the Business Combination Agreement) and one Acquiror Right (as defined in the Business Combination Agreement) in accordance with the terms of the applicable Acquiror Unit (the “Unit Separation”); (b) each Acquiror Right issued and outstanding immediately prior to the First Merger Effective Time were automatically converted into one-tenth of an Acquiror Ordinary Share (the “Acquiror Right Conversion”); and (c) immediately following the Unit Separation and Acquiror Right Conversion, each Acquiror Ordinary Share (which, for the avoidance of doubt, includes the Acquiror Ordinary Shares held as a result of the Unit Separation and the Acquiror Right Conversion) issued and outstanding immediately prior to the First Merger Effective Time were automatically cancelled and cease to exist in exchange for the right to receive one newly issued PubCo Ordinary Share; and (ii) at the Second Merger Effective Time (as defined in the Business Combination Agreement), each Company Exchanging Share (as defined in the Business Combination Agreement) were automatically cancelled and converted into the right of each holder of the Company Exchanging Shares to receive, such number of newly issued PubCo Ordinary Shares, as determined in accordance with the Business Combination Agreement, based on an exchange ratio equal to the quotient of (a) $5.568 billion divided by $10.00 per share, divided by (b) the number of Company Ordinary Shares issued and outstanding immediately prior to the Second Merger Effective Time.

In connection with the Business Combination, SLBT entered into subscription agreements (the “Subscription Agreements” and the transactions contemplated under the Subscription Agreements, the “PIPE Financing”) with certain investors (the “PIPE Investors”), pursuant to which the PIPE Investors committed to purchase an aggregate of 780,000 units of SLBT (the “PubCo Units”), in a private placement for a purchase price of $10.00 per PubCo Unit. Each PubCo Unit consists of (i) one PubCo Ordinary Share and (ii) one series A preferred share of SLBT, par value $0.00001 per share (the “PubCo Preferred Shares” or “Preferred Shares”). Each PubCo Preferred Share will be converted into one-third (1/3) of one PubCo Ordinary Share (such converted PubCo Ordinary Shares, the “Conversion Shares”) on the six-month anniversary of the closing of the Business Combination. The PIPE Financing closed in conjunction with the closing of the Business Combination.

The Business Combination was approved at the extraordinary general meeting of HSPT’s shareholders held on February 12, 2026 (the “Extraordinary General Meeting”). HSPT’s shareholders also voted to approve all other proposals presented at the Extraordinary General Meeting. The Business Combination was consummated on June 12, 2026. As a result of the Business Combination, On June 15, 2026, PubCo Ordinary Shares commenced trading on the Nasdaq Stock Market (“Nasdaq”) under the symbol “SLBT.”

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