Hansaitai-B (03378) will be open for subscription from December 15 to December 18, and is expected to be listed on December 23.

Hansy Atai-B (03378) will hold a public offering from December 15 to December 18, 2025, planning to globally sell 18.321 million shares, with 10% sold in Hong Kong and 90% sold internationally, at a price of HK$28-32 per share. Trading of shares is expected to begin on the Hong Kong Stock Exchange on December 23, 2025. The company is a biotechnology company with expertise in structural biology, translational medicine, and clinical development. Since 2016, the company has developed a pipeline of products, including a core product and nine other candidates, including three clinical-stage candidates for oncology, such as the company's core product HX009 and its main products HX301 and HX044, and seven preclinical-stage candidates for autoimmune and oncology markets, such as antibody-drug conjugates, bispecific antibodies, and monoclonal antibodies. The company has also developed HX008, which has been transferred to a biopharmaceutical company specializing in cancer therapy. The company's core product HX009 is a self-developed dual-function antibody fusion protein targeting PD-1 (an immune checkpoint receptor) and SIRP. The company has completed Phase I clinical trials of HX009 in Australia and China during the reporting period and up to the latest feasible date. The company is currently conducting three HX009 clinical projects in China, including a Phase Ib study of HX009-I-01 for advanced melanoma, a Phase I/II study of HX009-II-02 for recurrent/refractory EBV-positive non-Hodgkin lymphoma, and a Phase IIa study of HX009-II-05 for advanced cholangiocarcinoma. In February 2025, the company also received approval from the National Medical Products Administration for a joint study of HX009 and trastuzumab in late-stage triple-negative breast cancer patients, with the first patient expected to be recruited by 2026. As of the latest feasible date, the company also has two major products, HX301 and HX044, both in clinical stages and focusing on cancer treatment. HX301 is a multi-target kinase inhibitor targeting key pathways such as CSF1R, ARK5, FLT-3, and CDK4/6. The company has completed Phase I clinical studies of HX301 approved by the NMPA and is currently conducting a Phase II clinical study in China for the combination therapy of HX301 and temozolomide for glioblastoma. HX044 is a novel dual-function anti-CTLA-4 (an immune checkpoint receptor) antibody fusion protein SIRP, aimed at enhancing the targeted efficacy of CTLA-4. The company is currently conducting Phase I/IIa clinical studies of HX044 for the treatment of advanced solid tumor malignancies in Australia and China. By discovering, developing, and commercializing precision therapies for cancer and autoimmune diseases, the company is committed to developing a new generation of immune therapies to help meet the unmet medical needs of patients in the global market. The company has entered into cornerstone investment agreements with Fidelity Resources, Sage Partners, CITIC Securities (related to Kuncang OTC options), TFI Investment Fund SPC (acting on behalf of its independent investment portfolio TFI Lakeside SP), Main Source Capital Limited, YStem Capital, and Chunlei Capital Limited. The cornerstone investors have agreed to subscribe or cause the subscription of the number of shares listed in the table below at the offering price, subject to certain conditions. Based on the offering price of HK$32.00 per share (i.e., the highest offering price mentioned in this prospectus), the cornerstone investors will subscribe to a total of 2.9178 million shares. The company estimates that, after deducting underwriting commissions, expenses, and estimated expenses payable for the global offering, considering any additional discretionary incentive and assuming the non-exercise of the over-allotment option, the company will receive a net amount of approximately HK$496 million from the global offering at the offering price of HK$30.00 per H share (i.e., the midpoint of the indicative offering price range in this document). The company currently intends to use the net proceeds from the global offering as follows: approximately 35% for the development of the company's core product (HX009); approximately 33% for the development of the company's main products (HX301 and HX044); approximately 17% for the development of other important products of the company; approximately 5% for providing funding for commercialization and/or business development activities; approximately 10% for working capital and other general corporate purposes.