Company Announcements

CAMBRIDGE, Mass., ROTTERDAM, Netherlands and SHANGHAI, March 22, 2026 /PRNewswire/ -- Harbour BioMed (HKEX: 02142, the "Company"), a global biopharmaceutical company committed to the discovery and development of novel antibody therapeutics focusing on immunology and immune-oncology, today announced the online publication of the first-in-human Phase I trial (NCT05790694/CTR20221961) of HBM9378 (also known as SKB378 or WIN378), led by Dr. Min Xu, Physician in Respiratory Medicine at Chengdu Fifth People's Hospital, in the peer-reviewed journal Drug Design, Development and Therapy. The favorable safety profile and extended half-life observed in this study support further exploration of HBM9378's effects in patients with severe immunological disorders.

HBM9378 is a novel, half-life extended fully human monoclonal antibody that targets thymic stromal lymphopoietin (TSLP) jointly developed by Harbour BioMed and Kelun-Biotech. In the randomized, double-blind, placebo-controlled, single-ascending-dose (SAD) study, 50 healthy adult subjects were enrolled to evaluate the safety, tolerability, pharmacokinetics (PK) and immunogenicity of HBM9378. The dose-escalation study enrolled ten healthy subjects per cohort (20 mg, 60 mg, 200 mg, 600 mg, and 900 mg), with eight receiving HBM9378 and two receiving the placebo at each dose level.

Data showed that the incidence of treatment-emergent adverse events (TEAEs) was comparable between the HBM9378 dose groups and the placebo group, with no trend for increasing safety risks with dose escalation. The median time to maximum concentration (T_max) ranged from 4.05 to 14.1 days, and the mean half-life (T_1/2) ranged from 55.0 to 65.8 days. HBM9378 exposure (C_max and AUC) increased in an approximately dose-proportional manner across the dose range of 20 to 900 mg. The incidence of anti-drug antibody (ADA) was 5% (2/40) during the study period without clinical correlate or impact on drug exposure. No injection site reactions were observed in any dose group.

"The positive Phase I results for HBM9378 mark a significant milestone in our mission to develop innovative therapies for immunological diseases," said Dr. Jingsong Wang, Founder, Chairman, and CEO of Harbour BioMed. "The favorable safety profile and extended half-life observed reinforce our confidence in HBM9378's potential to address unmet medical needs in conditions like severe asthma and chronic obstructive pulmonary disease (COPD)."

"This Phase I clinical trial demonstrates that HBM9378 is well-tolerated and exhibits a favorable pharmacokinetic profile in healthy subjects," said Dr. Min Xu, Physician in Respiratory Medicine, Chengdu Fifth People's Hospital and Principal Investigator of this study. "The extended half-life of HBM9378 may reduce dosing frequency in clinical practice, potentially enhancing patient adherence and improving outcomes. These findings support further clinical development to evaluate its efficacy in patients with severe immunological disorders, and we hope to see more promising data in subsequent clinical trials to further demonstrate its efficacy in patients with immunological disorders."

About HBM9378 (SKB378/WIN378)

HBM9378 (also known as SKB378/WIN378) is a potentially best-in-class, long-acting monoclonal antibody targeting thymic stromal lymphopoietin (TSLP), a well-validated cytokine that plays a key role in the development and progression of a wide array of immunological diseases, including asthma and chronic obstructive pulmonary disease (COPD). This molecule has fully human sequences, offering a lower risk of immunogenicity and improved bioavailability. It has been engineered to achieve a half-life extension and a silenced effector function and is subcutaneously administered.

HBM9378 started as a co-development project jointly conducted by Harbour BioMed and Kelun-Biotech, with both parties equally sharing global rights. In January 2025, Harbour BioMed and Kelun-Biotech entered into a strategic partnership with Windward Bio, granting Windward Bio an exclusive license to research, develop, manufacture, and commercialize this antibody globally, excluding Greater China and several Southeast and West Asian countries.

Currently, Harbour BioMed has completed a Phase I clinical trial in China under an Investigational New Drug (IND) application for the treatment of moderate-to-severe asthma. A global Phase II POLARIS trial for this indication was initiated by Windward Bio in July 2025. In addition, the National Medical Products Administration (NMPA) of China has approved the IND application of HBM9378 for the treatment of COPD.

About Harbour BioMed

Harbour BioMed (HKEX: 02142) is a global biopharmaceutical company committed to the discovery and development of novel antibody therapeutics in immunology, oncology and other areas. The Company is building a robust portfolio and differentiated pipeline through internal R&D capability, strategic global collaborations in co-discovery and co-development, and selective acquisitions.

Our proprietary antibody technology platform, Harbour Mice^®, generates fully human monoclonal antibodies in both the conventional two heavy and two light chain (H2L2) format and the heavy chain-only (HCAb) format. Building upon HCAb antibodies, the HCAb-based immune cell engagers (HBICE^®) bispecific antibody technology enables tumor-killing effects that traditional combination therapies cannot achieve. The HCAb-based Antibody Plus technology (HCAb PLUS^TM) provides comprehensive modality solutions for the development of innovative multi-specific medicines in different disease areas. Additionally, building upon the Harbour Mice^® platform, Harbour BioMed launched its first fully human Generative AI HCAb Model powered by its Hu-mAtrIx^TM AI platform, accelerating the development of innovative therapies.

By integrating Harbour Mice^®, HBICE^®, HCAb PLUS^TM, a single B-cell cloning platform and AI technologies, Harbour BioMed has built a highly efficient and distinctive antibody discovery engine for developing next-generation therapeutic antibodies. For more information, please visit www.harbourbiomed.com.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects with 8 indications have been approved for marketing, more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects with 5 indications approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage.

About Windward Bio AG

Windward Bio is a clinical-stage biotechnology company with deep discovery, development, and commercialization expertise committed to transforming the treatment of people living with advanced immunological conditions. Its lead program is WIN378, a potential best-in-disease, long-acting anti-TSLP monoclonal antibody currently in Phase 2 trials for asthma. The pipeline also includes WIN027, a clinical-stage, long-acting anti-TSLP×IL-13 bispecific, which has broad therapeutic application across immunological diseases. The company is building a pipeline of long-acting bispecific antibodies, targeting validated biology in respiratory and dermatological conditions.

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SOURCE Harbour BioMed