Windward Bio seeks Nasdaq listing after raising $365 million

By Daniel Okafor

Windward Bio disclosed in its regulatory filing that it had applied to list its common shares on the Nasdaq Global Market after raising up to $365.0 million.

The filing described the Basel-based company as a clinical-stage biotechnology business focused on immunological diseases. Windward Bio launched in January 2025, in-licensed two clinical-stage assets and advanced both programs into the clinic.

What is Windward Bio building?

The filing says Windward Bio develops ultra-long-acting antibody medicines for serious respiratory and dermatologic diseases. Its targets include asthma, chronic obstructive pulmonary disease, or COPD, and atopic dermatitis.

According to the filing, WIN378 and WIN027 target clinically validated disease pathways. The company engineered its candidates to remain in the body for extended periods, enabling less frequent dosing than currently available treatments.

The design also includes enhanced target affinity, dual target binding or effector function silencing. The shared objective is longer antibody exposure without abandoning disease pathways that earlier studies have validated.

What do WIN378's early results show?

Windward Bio is evaluating WIN378 in POLARIS-1, a Phase 2/3 study in severe uncontrolled asthma. The company began start-up work for a second Phase 3 trial, POLARIS-2, in September 2026. Patient recruitment is planned for the first half of 2027.

The company also initiated the Phase 2 SIRIUS study of WIN378 in COPD in June 2026. Windward Bio completed a pre-planned analysis of the Phase 2 portion of POLARIS-1 in the second half of 2026.

Windward Bio reported that WIN378 was well tolerated. No treatment-related serious adverse events, withdrawals or discontinuations had been observed to date.

WIN378 showed an observed half-life of up to 75 days. At week 24, the company observed improvements in lung function and biomarkers of airway inflammation.

Windward Bio said those results support twice-yearly subcutaneous dosing and the potential for improved clinical outcomes. The filing did not quantify the lung-function or biomarker improvements.

How does WIN027 work?

The filing identifies WIN027 as an ultra-long-acting bispecific antibody that simultaneously targets TSLP and interleukin-13, or IL-13. It describes both targets as clinically validated drivers of inflammatory disease.

WIN027 is being tested in a Phase 1 healthy-volunteer study assessing safety and pharmacokinetics. According to the filing, investigational new drug applications, or INDs, are open in the United States, Australia and the People's Republic of China.

Windward Bio reported a 62-day half-life in an interim Phase 1 analysis. The company also observed low immunogenicity and a low rate of injection site reactions.

Who leads the company?

Windward Bio was founded in 2024 and launched in January 2025. Founder, Chief Executive Officer and Chairman Luca Santarelli, M.D., leads the management team.

Santarelli has more than 25 years of academic and biopharmaceutical research and development experience. He previously co-founded and served as Chief Executive Officer of VectivBio, which Ironwood Pharmaceuticals acquired in 2023 for $1.2 billion.

He also co-founded and served as Chief Executive Officer of Therachon, which Pfizer acquired in 2019 for up to $810 million.

Who has backed the financing?

Windward Bio said equity financings have raised up to $365.0 million to date. The company said the financings were led by OrbiMed, Novo Holdings, SR One, Omega Funds, Blue Owl Healthcare Opportunities and RTW Investments.

Windward Bio described the group as top-tier global healthcare investors. The disclosed total provides financing for two clinical programs, but the company has yet to publish terms for the Nasdaq offering.

How will the offering proceeds be used?

Windward Bio intends to use the offering's net proceeds for three priorities:

• Fund completion of the ongoing POLARIS-1 Phase 2/3 trial and confirmatory POLARIS-2 Phase 3 trial of WIN378 in asthma; the ongoing SIRIUS Phase 2 trial of WIN378 in COPD; and related research and development activities.
• Complete the planned global Phase 2b trial of WIN027 in COPD and the planned global Phase 2 trial of WIN027 in atopic dermatitis; fund related research and development activities.
• Advance the company's bispecific programs through IND-enabling studies.

What remains undisclosed?

The filing disclosed no number of shares to be offered, price range or timetable. Investors therefore have no offering price or implied valuation in the regulatory document.

For investors, the next checkpoints are POLARIS-2 recruitment in the first half of 2027 and Windward Bio's planned global WIN027 trials. The offering's share count, price range and timetable remain undisclosed.