We are a clinical-stage biotechnology company developing ultra-long-acting antibody medicines for patients with serious respiratory and dermatologic diseases, including asthma, chronic obstructive pulmonary disease, or COPD, and atopic dermatitis. We estimate these diseases collectively represent a $60 billion peak market opportunity for biologic therapies, as we believe the majority of patients eligible to receive biologic treatment for these diseases remain untreated. Our product candidates can potentially address this significant unmet need, allow for treatment of a broader population of patients, improve efficacy, and improve dosing convenience and adherence to treatment. We estimate that these diseases collectively affect more than 100 million people in the United States, EU5 (France, Germany, Italy, Spain, and the United Kingdom), and Japan and more than 8 million are eligible for biologics treatment.

Our product candidates, WIN378 and WIN027, target clinically validated disease pathways and are engineered to remain in the body for extended periods of time, enabling less frequent dosing than currently available treatments. This design feature is combined with additional properties including enhanced target affinity, dual target binding or effector function silencing. We believe our product candidates have the potential to deliver better clinical outcomes while offering the convenience of less frequent dosing than currently available treatments.

WIN378 for ASTHMA & COPD

WIN378 is an ultra-long-acting and potentially novel fully human monoclonal antibody that is designed to inhibit thymic stromal lymphopoietin, or TSLP. TSLP is positioned upstream of multiple inflammatory pathways and is a clinically validated target in respiratory disease. WIN378 is currently being evaluated in POLARIS-1, a Phase 2/3 study in severe uncontrolled asthma. Study start-up activities were initiated in September 2026 for a second Phase 3 study (POLARIS-2), which is planned to begin patient recruitment in the first half of 2027.

A Phase 2 study of WIN378 in COPD, SIRIUS, was initiated in June 2026. A pre-planned analysis of the Phase 2 portion of POLARIS-1 was completed in the second half of 2026. This model-informed Phase 2 portion characterized the dose-response relationship and enrolled 147 patients, exceeding the enrollment target of 120 patients. WIN378 was well-tolerated, with no treatment-related serious adverse events, withdrawals or discontinuations observed to date. Adverse events were balanced between active arms and placebo, with low rates of injection site reactions and antidrug antibodies. WIN378 had an observed half-life of up to 75 days and improvements in lung function and biomarkers of airway inflammation at week 24 were observed, which we believe support twice-yearly subcutaneous dosing and the potential for improved clinical outcomes. Two twice-yearly dose levels were selected, and the Phase 3 portion of POLARIS-1 was initiated in September 2026. We expect that the next data readout for WIN378 will be the Phase 2 primary results at week 24 in the first half of 2027.

WIN0027 for COPD & ATOPIC DERMATITIS

WIN027 is an ultra-long-acting bispecific antibody that simultaneously targets TSLP and interleukin-13, or IL-13, two clinically validated drivers of inflammatory disease. We believe that dual inhibition of these pathways has the potential to deliver deeper and more durable disease control than targeting either pathway alone. WIN027 is currently in a Phase 1 healthy volunteer study with investigational new drug applications, or INDs, open in the United States, Australia and the People’s Republic of China, or the PRC, assessing safety and pharmacokinetics. In an interim analysis of the Phase 1 study, we observed a 62-day half-life, low immunogenicity and low rate of injection site reactions, with full pharmacokinetic and immunogenicity data expected in the first half of 2027. We initiated study start-up activities in September 2026 in a global Phase 2b study in COPD powered on the registrational endpoint of exacerbation rate ratio and a second global Phase 2 study in atopic dermatitis, which are planned to begin patient recruitment in the first half of 2027. Our partner Qyuns Therapeutics Co., Ltd., or Qyuns, initiated their Phase 2 studies in atopic dermatitis and chronic rhinosinusitis with nasal polyps, or CRSwNP, in September 2026 in the PRC and plans to begin a Phase 2 study in asthma by the end of the year. Topline results from these studies are expected over the course of 2027 and 2028.

Note: Net loss is in U.S. dollars for the 12 months that ended on June 30, 2026. 

(Windward Bio Group AG filed its F-1 for its IPO on Oct. 23, 2026, without disclosing the terms. Estimated proceeds are $100 million.)