• COPD study initiation expands SKB378/WIN378 development into a second major respiratory disease
• SKB378/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
• SKB378/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

Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company") today announced that its partner Windward Bio has dosed the first patients in the Phase 2 SIRIUS study of SKB378/WIN378 (also known as HBM9378) 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 SKB378/WIN378 in patients with moderate-to-severe COPD.

SKB378/WIN378 started as a co-development project jointly conducted by the Company and Harbour BioMed, with both parties equally sharing global rights.