Windward Bio Raises $165M for Immunology Drug Pipeline

Windward Bio has successfully closed a substantial $165 million crossover financing round, bolstering its capacity to advance a promising portfolio of long-acting immunology therapies. The significant capital infusion, led by prominent healthcare investor OrbiMed, underscores strong market confidence in the company's strategy to address unmet needs in severe immunological conditions.

The funding round saw robust participation from both new and existing investors. Alongside OrbiMed, the syndicate includes RA Capital Management, Janus Henderson Investors, Sanofi Ventures, and Harbour BioMed. Existing backers such as Novo Holdings, Blue Owl Healthcare Opportunities, SR One, Omega Funds, RTW Investments, Qiming Venture Partners, Quan Capital, and Pivotal bioVenture Partners also contributed, demonstrating continued support for Windward Bio's development trajectory.

Proceeds from this financing are earmarked to propel the company's lead candidate, WIN378, into Phase 3 clinical trials. This next-generation anti-TSLP antibody is engineered for ultra-long-acting efficacy, potentially enabling twice-yearly administration for conditions like asthma and COPD. The funds will also support the advancement of WIN027, a bispecific antibody targeting TSLP and IL-13, into respiratory and dermatology studies by the fourth quarter of 2026. This dual-targeting approach aims for best-in-disease outcomes in inflammatory conditions.

The strategic importance of this financing is amplified by Windward Bio's rapid progress since its inception in January 2025. The company has already secured two clinical-stage assets and raised a total of $365 million, demonstrating an agile approach to pipeline development. The current funding extends the company's operational runway, positioning it for multiple clinical readouts within the next twelve months. The market for biologics targeting inflammatory pathways, particularly those offering extended dosing intervals, is experiencing significant growth, driven by patient demand for improved convenience and sustained therapeutic benefit.

WIN378, a fully human monoclonal antibody, targets the thymic stromal lymphopoietin (TSLP) ligand, a critical mediator in numerous immunological diseases. Its half-life extension technology and silenced effector function are key differentiators. Initial Phase 1 data confirmed its extended half-life, safety, and tolerability, supporting the twice-yearly dosing regimen. The drug is currently under evaluation in the Phase 2/3 POLARIS asthma program, with initial data anticipated in the latter half of 2026. A Phase 2 study in chronic obstructive pulmonary disease (COPD) is slated to commence in the second quarter of 2026, preceding the first Phase 3 study in Q4 2026.

WIN027 represents a novel bispecific antibody designed to simultaneously inhibit TSLP and IL-13, two synergistic drivers of inflammation. This dual mechanism holds potential for enhanced efficacy in severe asthma, COPD, and atopic dermatitis. Currently in Phase 1 trials, with data expected by year-end 2026, WIN027's development will be accelerated across multiple indications starting in Q4 2026. The company has secured global rights for WIN378 (excluding Greater China and select Asian regions) from Kelun-Biotech and Harbour BioMed, and for WIN027 (excluding Greater China) from Qyuns Therapeutics.

Dr. Luca Santarelli, Founder, CEO, and Board Chair of Windward Bio, expressed enthusiasm for the expanded investor base and the strengthened financial position. He highlighted the company's focus on developing next-generation therapies for patients suffering from serious respiratory and dermatological diseases. David Bonita, General Partner at OrbiMed, echoed this sentiment, emphasizing Windward Bio's unique position and differentiated portfolio poised to elevate care standards in immunology.