Windward Bio, a private, clinical-stage biotechnology company based in Basel, Switzerland, has announced an upsized $165 million crossover financing led by OrbiMed, with participation from RA Capital Management, Janus Henderson Investors, Sanofi Ventures, Harbour BioMed, and existing investors. Proceeds will significantly extend the company’s cash runway and enable multiple clinical readouts in the next 12 months, including advancing its lead candidate WIN378 into Phase 3 and WIN027 into respiratory and dermatology studies by the fourth quarter of 2026.
Since launching in January 2025, Windward Bio has in-licensed two clinical-stage assets, raised $365 million in total, and rapidly advanced both programs in the clinic. WIN378, the lead program, is a next-generation, fully human monoclonal antibody targeting the thymic stromal lymphopoietin cytokine, known as TSLP, which 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, and is currently being studied in the Phase 2/3 POLARIS program in asthma, with initial data expected in the second half of 2026. A Phase 2 study in chronic obstructive pulmonary disease is anticipated to begin in the second quarter of 2026.
WIN027, the company’s second program, is a highly potent, long-acting bispecific antibody targeting both TSLP and interleukin-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, with multiple proof-of-concept studies across respiratory and dermatology indications set to begin in the fourth quarter of 2026.
Existing Series A investors participating in the financing include Novo Holdings, Blue Owl Healthcare Opportunities, SR One, Omega Funds, RTW Investments, Qiming Venture Partners, Quan Capital, and Pivotal bioVenture Partners. The round reflects strong institutional confidence in Windward Bio’s differentiated portfolio and its potential to raise the standard of care in respiratory and dermatology.
KEY QUOTES:
“We are excited to expand our shareholder base of top-tier investors to include RA Capital, Janus Henderson Investors, and Sanofi Ventures. This financing further strengthens our balance sheet and allows us to advance our programs of next-generation therapies for patients living with serious respiratory and dermatological diseases.”
— Luca Santarelli, MD, Founder, Chief Executive Officer, and Board Chair, Windward Bio
“Windward Bio is uniquely positioned to make an impact in immunology with a differentiated portfolio that could raise the standards of care in respiratory and dermatology. We are impressed with the significant progress the Windward Bio team has made since the company’s launch in 2025 and are proud to lead this high-caliber investor syndicate in supporting Windward Bio’s mission to discover and develop novel therapeutics for serious immunological conditions.”
— David Bonita, General Partner, OrbiMed