Kelun-Biotech's Partner Windward Bio Announces Initiation of a Global Phase 2 Asthma Trial of SKB378/WIN378

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CHENGDU, China, July 23, 2025 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or "the Company", HKEX: 6990) today announced that its partner, Windward Bio AG ("Windward Bio") has launched its Phase 2 POLARIS clinical study, assessing long-acting dosing of SKB378/WIN378 for people living with asthma.

SKB378/WIN378 is a novel, recombinant fully human monoclonal antibody (mAb) that potently binds to the thymic stromal lymphopoietin (TSLP) ligand and inhibits the TSLP mediated signaling pathway by blocking the interaction between TSLP and TSLP receptor. This is a well-validated cytokine that plays a key role in the development and progression of a wide array of immunological conditions, including asthma and chronic obstructive pulmonary disease (COPD) where inhibition has demonstrated benefit in a wide array of inflammatory phenotypes. SKB378/WIN378 has been engineered to achieve an extended half-life and effector silencing and is subcutaneously administered. SKB378/WIN378 has been studied in a Phase 1 trial which confirmed the half-life for extended dosing, demonstrated a low rate of antidrug antibodies, and was safe and well tolerated up to the highest tested dose. 

The Phase 2 POLARIS trial is a global, randomized, double-blind, placebo-controlled study evaluating the dosing, safety, and efficacy of SKB378/WIN378 in patients with asthma. Initial data is expected in mid-2026. Additional clinical trials are planned with SKB378/WIN378 including in COPD in 2026. In January 2025, an IND application for SKB378/WIN378 for the treatment of COPD was approved by the National Medical Products Administration (NMPA).

SKB378/WIN378 started as a co-development project jointly conducted by the Company and Harbour BioMed (also known as HBM9378), with both parties equally sharing global rights. In January 2025, it was announced that the Company and Harbour BioMed had entered into an exclusive license agreement with Windward Bio, under which the Company and Harbour BioMed granted Windward Bio an exclusive license for the research, development, manufacturing and commercialization of SKB378/WIN378 globally (excluding Greater China and several Southeast and West Asian countries).

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical (002422.SZ), which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. The company focuses on major disease areas such as solid tumors, autoimmune, inflammatory, 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. The Company is committed to becoming a leading global enterprise in the field of innovative drugs. At present, the Company has more than 30 ongoing key innovative drug projects, of which 3 projects have been approved for marketing, 1 project is in the NDA stage, and more than 10 projects are in the clinical stage. The company has established one of the world's leading proprietary ADC platforms, OptiDC™, and has 1 ADC project approved for marketing, 1 ADC project in NDA stage, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://kelun-biotech.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 advanced immunological conditions. Its lead program is WIN378, a potential best-in-disease, long-acting, anti-TSLP monoclonal antibody in Phase 2 for asthma. The company is planning additional clinical studies of WIN378 in COPD and other respiratory indications and is also building a pipeline of long-acting bi-specifics targeting validated biology in respiratory and dermatological conditions. Windward Bio launched earlier this year with a $200M Series A led by top-tier investors.

SOURCE Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd.