• COPD study initiation expands HBM9378/WIN378 (also known as SKB378) development into a second major respiratory disease
• HBM9378/WIN378 is currently being evaluated in the Phase 2/3 POLARIS asthma study, with initial Phase 2 data expected in the second half of 2026
• HBM9378/WIN378 has the potential to be the first-to-market, ultra long-acting anti-TSLP antibody for asthma and COPD, with Phase 3 initiation in asthma planned for Q4 2026

CAMBRIDGE, Mass., ROTTERDAM, Netherlands and SHANGHAI, June 9, 2026 /PRNewswire/ -- Harbour BioMed (the "Company"; HKEX: 02142), a global biopharmaceutical company committed to the discovery and development of novel antibody therapeutics in immunology, oncology and other disease areas, today announced that its partner Windward Bio has dosed the first patients in the Phase 2 SIRIUS study of HBM9378/WIN378 (also known as SKB378) in patients with chronic obstructive pulmonary disease (COPD).

COPD is a progressive, irreversible lung disease and the third leading cause of death worldwide. Driven by immune-mediated airway inflammation and persistent airflow obstruction, the disease makes even routine daily activities a struggle. Its defining feature is exacerbations — sudden, severe flare-ups that lead to emergency room visits, hospitalizations, and lasting declines in lung function. Despite currently available inhaled background therapies, more than 3 million patients with moderate-to-severe COPD remain at high risk of recurrent exacerbations, underscoring an urgent need for better treatment options.

SIRIUS is a global, Phase 2 randomized, double-blind, placebo-controlled, dose-finding study. It is designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of HBM9378/WIN378 in patients with moderate-to-severe COPD.

"We are very pleased to see the continued clinical advancement of HBM9378/WIN378 by our partner Windward Bio with the initiation of the Phase 2 SIRIUS COPD study," said Dr. Jingsong Wang, Founder, Chairman and CEO of Harbour BioMed. "This milestone further highlights the potential of HBM9378/WIN378 as a differentiated, ultra long-acting anti-TSLP antibody for immunological diseases. As one of the originators of this promising molecule and a new investor in Windward Bio, we strongly believe in the potential of HBM9378/WIN378 and Windward Bio's execution capabilities. We look forward to supporting the continued advancement of the program and ultimately bringing innovative treatment options to patients living with COPD worldwide."

About HBM9378/WIN378

HBM9378/WIN378 (also known as SKB378) is a next-generation, fully human monoclonal antibody that potently inhibits the TSLP ligand. This clinically validated target plays a key role in the development and progression of a wide array of immunological diseases, including asthma and COPD. HBM9378/WIN378 has been engineered to achieve half-life extension (HLE) and have a silenced effector function. It has been studied in a Phase 1 trial, which confirmed an extended half-life suitable for twice-yearly dosing, demonstrated a low rate of antidrug antibodies, and was safe and well tolerated up to the highest dose tested. HBM9378/WIN378 is administered subcutaneously. Windward Bio licensed the global rights (excluding Greater China and several Southeast and West Asian countries) for WIN378 from Harbour BioMed (also known as HBM9378) and Kelun-Biotech (also known as SKB378). HBM9378/WIN378 is currently being evaluated in the POLARIS Phase 2/3 asthma study with initial readouts expected in the second half of 2026. HBM9378/WIN378 is also being evaluated in the SIRIUS Phase 2 COPD study. The first Phase 3 study of HBM9378/WIN378 in asthma is expected to begin in the fourth quarter of 2026.

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 Windward Bio

Windward Bio is a clinical-stage biotechnology company with deep discovery, development, and commercialization expertise committed to transforming the treatment of people living with serious immunological conditions. Its lead program is WIN378, a potential best-in-disease, ultra long-acting anti-TSLP monoclonal antibody currently in a Phase 2/3 trial for asthma and in a Phase 2 study for COPD. The pipeline also includes WIN027, a clinical-stage, long-acting anti-TSLPxIL-13 bispecific with broad therapeutic potential across immunological diseases, which is currently in Phase 1. The company is building a discovery pipeline of long-acting bispecific antibodies, targeting validated biology in respiratory and dermatological conditions.