

News
May 4, 2026
Led by OrbiMed, with participation from RA Capital Management, Janus Henderson Investors, Sanofi Ventures, and existing investors, including Novo Holdings
Proceeds will advance lead candidate WIN378 into Phase 3 and WIN027 into respiratory and dermatology studies by Q4 2026
WIN378 has the potential to be the first-to-market ultra long-acting anti-TSLP antibody for asthma and COPD
WIN027 is a long-acting bispecific targeting TSLP and IL-13 with best-in-disease efficacy potential
Windward Bio, a private, clinical-stage biotechnology company committed to improving outcomes for people living with serious immunological diseases, today announced an upsized $165 million crossover financing led by OrbiMed, with participation from existing Series A investors including Novo Holdings, Blue Owl Healthcare Opportunities, SR One, Omega Funds, RTW Investments, Qiming Venture Partners, Quan Capital, and Pivotal bioVenture Partners. The financing also included new investors RA Capital Management, Janus Henderson Investors, and Sanofi Ventures.
Proceeds will significantly extend the company’s cash runway and enable multiple clinical readouts in the next 12 months.
Since launching in January 2025, Windward Bio has in-licensed 2 clinical-stage assets, raised $365 million, and rapidly advanced both programmes[RW1] in the clinic. WIN378, the lead programme, is a next-generation, fully human monoclonal antibody that potently binds to the thymic stromal lymphopoietin (TSLP) ligand. This well-validated cytokine plays a key role in the development and progression of a wide array of immunological diseases. WIN378 has the potential to be the first-to-market, ultra long-acting anti-TSLP antibody with twice-yearly dosing.
The financing will accelerate the development of WIN378, which is currently being studied in the Phase 2/3 POLARIS programme in asthma. The Phase 2 dose-ranging component of POLARIS is fully recruited, with initial data expected in the second half of 2026. The first Phase 3 study of WIN378 is expected to begin in the fourth quarter of 2026. The Phase 2 SIRIUS study in chronic obstructive pulmonary disease (COPD) is anticipated to start in the second quarter of 2026.
WIN027, the second programme, is a highly potent, long-acting bispecific antibody targeting both TSLP and interleukin-13 (IL-13) – two well-validated and synergistic drivers of inflammation in severe asthma, COPD, and atopic dermatitis. WIN027 is currently in a Phase 1 study with data readout expected by the end of 2026. The financing will support multiple proof-of-concept studies across respiratory and dermatology indications starting in in the fourth quarter of 2026.
“We are excited to expand our shareholder base of top-tier investors to include RA Capital, Janus Henderson, and Sanofi Ventures” said Luca Santarelli, MD, Founder, Chief Executive Officer, and Board Chair of Windward Bio. “This financing further strengthens our balance sheet and allows us to further advance our programmes of next-generation therapies for patients living with serious respiratory and dermatological diseases.”
Naveed Siddiqi, Senior Partner, Venture Investments, Novo Holdings, said: “Spearheaded by a highly experienced clinical and commercial leadership consisting of serial entrepreneurs, Windward Bio has made rapid progress since it launched in 2025, including bringing in a second clinical stage asset, WIN027. There is much more to be done towards improving dosing frequency and outcomes for the benefit of patients suffering from serious and chronic immunological conditions, and as a significant shareholder, we are pleased to support Windward Bio as it advances its innovative and developing pipeline into late-stage trials.”
About WIN378
WIN378 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. WIN378 has been engineered to achieve half-life extension (HLE) and to 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. WIN378 is administered subcutaneously. Windward Bio licensed the global rights (excluding Greater China and several Southeast and West Asian countries) for WIN378 from Kelun Biotech (also known as SKB378) and Harbour BioMed (also known as HBM9378). WIN378 is currently being evaluated in the POLARIS Phase 2/3 asthma study with initial readouts expected in the second half of 2026. A Phase 2 study in COPD is anticipated to begin in the second quarter of 2026.
About WIN027
WIN027 is a potential best-in-class, humanised bispecific monoclonal antibody with subpicomolar affinity for TSLP and IL-13, well-validated targets in immunological conditions. It has been engineered to achieve an extended half-life and enable less frequent dosing. Through this dual, long‑acting inhibition, WIN027 is designed to set a new standard of efficacy in conditions such as asthma, COPD, and atopic dermatitis, potentially delivering deeper and more durable disease control than existing biologics. WIN027 is currently in Phase 1. Windward Bio licensed the global rights (excluding Greater China) for WIN027 from Qyuns Therapeutics (also known as QX027N).
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 programme is WIN378, a potential best-in-disease, ultra long-acting anti-TSLP monoclonal antibody currently in a Phase 2/3 trial for asthma. 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.
Media Enquiries
Marie-Louise Jersin, Senior Communications Lead, maj@novo.dk