Windward Bio AG has secured an exclusive global license for SKB378/HBM9378, an anti-thymic stromal lymphopoietin (TSLP) monoclonal antibody, from Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. and HBM Holdings Limited (Harbour BioMed). The agreement, announced on January 11, 2025, grants Windward Bio the rights to research, develop, manufacture, and commercialize the antibody, excluding Greater China and several Southeast and West Asian countries. This strategic move positions Windward Bio to advance SKB378/HBM9378, a potential best-in-class TSLP inhibitor, into Phase 2 clinical trials for severe respiratory conditions.
Financial Terms of the Agreement
Under the terms of the license agreement, Kelun-Biotech and Harbour BioMed are eligible to receive up to $970 million in upfront and milestone payments, as well as tiered royalties on net sales of SKB378/HBM9378. The upfront and near-term payments include $45 million in cash and equity in Windward Bio's parent company. Additional payments are contingent upon a change of control or sublicense agreement by Windward Bio. The financial arrangement underscores the confidence in SKB378/HBM9378's potential and Windward Bio's commitment to its development.
SKB378/HBM9378: Targeting TSLP in Immunological Diseases
SKB378/HBM9378 is a recombinant fully human monoclonal antibody that inhibits the TSLP-mediated signaling pathway by blocking the interaction between TSLP and its receptor. TSLP is a cytokine implicated in the development and progression of various immunological conditions, including asthma and chronic obstructive pulmonary disease (COPD). Preclinical studies have demonstrated the benefit of TSLP inhibition across a range of inflammatory phenotypes. The antibody has been engineered for extended half-life and effector silencing and is administered subcutaneously.
Clinical Development and Regulatory Status
An Investigational New Drug (IND) application for SKB378/HBM9378 was submitted to China's National Medical Products Administration (NMPA) in November 2024 for the treatment of COPD. Kelun-Biotech has also completed a Phase 1 clinical trial in healthy subjects in China for the treatment of moderate-to-severe asthma, under IND approval from the NMPA.
Windward Bio's Strategic Focus and Funding
Windward Bio is a clinical-stage drug development company focused on improving outcomes for patients with advanced immunological conditions, with an initial emphasis on severe respiratory diseases. The company is backed by a $200 million Series A financing round led by OrbiMed, Novo Holdings, and Blue Owl Healthcare Opportunities, with co-investment from SR One, Omega Funds, RTW Investments, Qiming Venture Partners, Quan Capital, and Pivotal bioVenture Partners. This funding will support the advancement of SKB378/HBM9378 and the development of novel, long-acting bispecific programs for immunological diseases.
Executive Commentary
Dr. Micheal Ge, CEO of Kelun-Biotech, stated, "We are pleased to have entered into a partnership with Windward Bio for the SKB378/HBM9378... In the future, we will continue to expand our global presence and strategic partnerships to maximize the value of our pipelines."
