The principal business address of the Sponsor is c/o Horizon Space Acquisition II Corp., 1412 Broadway, 21st Floor, Suite 21V, New York, NY 10018. The principal business address of Mr. Li is c/o Horizon Space Acquisition II Corp., 1412 Broadway, 21st Floor, Suite 21V, New York, NY 10018.

The Sponsor is the sponsor of the Issuer and primarily involved in investment. Mr. Li beneficially owns 50% issued and outstanding shares of the Sponsor. In accordance with the governing documents of the Sponsor, Mr. Li is the sole director of the Sponsor and deemed to have the voting and dispositive rights over the securities of us held by the Sponsor.

During the past five years, none of the Reporting Persons or to the knowledge of the Reporting Persons, the persons identified in this Item 2, has been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was the subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal and state securities laws of findings any violation with respect to such laws.

During the past five years, none of the Reporting Persons or to the knowledge of the Reporting Persons, the persons identified in this Item 2, has been convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors).

The Sponsor is a exempted company incorporated in Cayman Islands. Mr. Li is a citizen of the People's Republic of China.

The information set forth in Items 4 and 5 of this Schedule 13D are hereby incorporated by reference into this Item 3.

Item 4 of the Schedule 13D is amended and supplemented as follows: Consummation of the Business Combination On June 12, 2026, HSPT consummated the previously announced business combination pursuant to the Business Combination Agreement, dated as of May 9, 2025 ( 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 the Business Combination Agreement, (i) Merger Sub I merged with and into HSPT, with HSPT as the surviving entity and a wholly-owned subsidiary of PubCo (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 PubCo (the "Second Merger," and together with the First Merger and the other transactions contemplated by the Business Combination Agreement, the "Business Combination"). Upon the consummation of the Business Combination, each of HSPT and SL Bio became a subsidiary of PubCo, and the shareholders of HSPT and SL Bio received ordinary shares of PubCo, par value $0.0001 per share ("PubCo Ordinary Shares"), as consideration and become shareholders of PubCo. Immediately prior to the First Merger Effective Time (as defined in the Business Combination Agreement), each HSPT Unit issued and outstanding was automatically detached, and the holder thereof was deemed to hold one (1) HSPT Ordinary Share and one (1) HSPT Right in accordance with the terms of the applicable unit (the "Unit Separation"). Each HSPT Right issued and outstanding was then automatically converted into one-tenth (1/10) of one HSPT Ordinary Share (the "Right Conversion"). Immediately following the Unit Separation and Right Conversion, each HSPT Ordinary Share (including those resulting from the Unit Separation and Right Conversion) issued and outstanding immediately prior to the First Merger Effective Time was automatically cancelled and ceased to exist in exchange for the right to receive one (1) newly issued PubCo Ordinary Share. Upon the consummation of the Business Combination on June 12, 2026, the Reporting Persons no longer beneficially owned any securities of HSPT, including any Ordinary Shares.

The responses to Items 7 - 13 of the cover pages of this Schedule 13D are incorporated herein by reference.

The responses to Items 7 - 13 of the cover pages of this Schedule 13D are incorporated herein by reference.

Other than the disposition of the shares as reported in this Schedule 13D, no actions in the ordinary shares were effected during the past sixty (60) days by the Reporting Persons.

N/A

As of June 12, 2026, the Reporting Persons ceased to beneficially own more than 5% of the issued and outstanding Ordinary Shares.

The information set forth in Items 4 of this Schedule 13D are hereby incorporated by reference into this Item 6.

Item 7 of the Schedule 13D is hereby amended by adding the following to the end of the section: 7.1 Joint Filing Agreement, dated November 19, 2024 10.1 Securities Purchase Agreement by and among the Registrant and the sponsor, dated as of July 25, 2024. 10.2 Securities Transfer Agreement, among the Registrant, the sponsor and the directors, dated as of July 26, 2024 10.3 Securities Transfer Agreement, among the Registrant, the sponsor and the CFO, dated as of July 26, 2024 10.4 Private Units Subscription Agreement dated November 14, 2024 between the Sponsor and the Issuer. 10.5 Business Combination Agreement, dated May 9, 2025, by and among Horizon Space Acquisition II Corp., SL Bio Ltd, SL Science Holding Limited, CW Mega Limited, and WW Century Limited.