An IPO is on the horizon for a Basel startup: biotech Windward Bio has applied to list its ordinary shares on the Nasdaq Global Market, Startupticker.ch reported on October 26, 2026. Launched in January 2025, the company says it has raised up to $365 million in equity. It develops ultra-long-acting antibodies against asthma, chronic obstructive pulmonary disease (COPD) and atopic dermatitis.
A listing application, not yet an IPO
Windward Bio has filed an application; it has not yet sold any shares on the stock market. The regulatory filing gives neither the number of shares offered, nor the price range, nor the timetable, according to Startupticker.ch. The amount the company hopes to raise therefore remains unknown.
This distinction matters for what follows. An IPO is only completed once the shares have been placed and the first listing has taken place. As long as these elements are missing, it is an announced plan.
Up to $365 million raised since January 2025
The young company was founded in 2024, then launched in January 2025. Since then, it has in-licensed two drug candidates already in clinical development. It has also raised up to $365 million, according to Startupticker.ch.
These funds were contributed as equity, in other words in exchange for stakes in the company. The rounds were led by investors including OrbiMed, Novo Holdings, SR One, Omega Funds, Blue Owl Healthcare Opportunities and RTW Investments. The breakdown of this amount by round has not been published.
Private fundraising generally goes through successive stages, from the seed funding round to Series A and the subsequent series. To place the stages and players in context, our guide explains how to raise funds in Switzerland.
Two long-acting antibodies in clinical trials
Windward Bio's two products target mechanisms already validated in the clinic, with less frequent injections. They are designed to remain in the body for a long time. They are candidates in development, not approved treatments.
- WIN378 is being tested in POLARIS-1, a phase 2/3 study in severe uncontrolled asthma. A planned analysis of the phase 2 part was completed in the second half of 2026.
- According to the company, WIN378 was well tolerated, with no serious treatment-related adverse events. Its observed half-life reaches up to 75 days.
- Improvements in lung function and in markers of airway inflammation were observed at week 24. The company sees this as support for two subcutaneous injections per year.
- A second phase 3 study, POLARIS-2, has been in preparation since September 2026. Patient enrollment is planned for the first half of 2027.
- A phase 2 study of WIN378 in COPD, called SIRIUS, started in June 2026.
- WIN027 is a bispecific antibody that targets both TSLP and interleukin 13. It is in phase 1 in healthy volunteers.
- An interim analysis of this phase 1 showed a half-life of 62 days. Trial applications are open in the United States, Australia and China.
What would the IPO money be used for?
Part of the net proceeds of the offering would go to WIN378, according to the filing cited by Startupticker.ch. It is to fund the completion of POLARIS-1, the POLARIS-2 confirmatory trial and the SIRIUS study in COPD.
The rest would go to WIN027: a global phase 2b study in COPD and a phase 2 study in atopic dermatitis. Its bispecific programs are also to advance to the studies required before a trial application.
A founder who has already sold two biotechs
Founder Luca Santarelli, a physician, heads Windward Bio and chairs its board of directors. He has more than 25 years of experience in academic and biopharmaceutical research.
He co-founded and led VectivBio, bought in 2023 by Ironwood Pharmaceuticals for $1.2 billion. He also co-founded Therachon, acquired in 2019 by Pfizer for up to $810 million.
Two Basel biotechs, two funding routes
A week earlier, another Basel biotech closed a private round, without going through the stock market. On October 19, 2026, Startupticker.ch announced Nouscom's Series D, worth $135 million.
| Benchmark | Windward Bio | Nouscom |
|---|---|---|
| Headquarters | Basel | Basel |
| Announcement | Nasdaq listing application, October 26, 2026 | Series D, October 19, 2026 |
| Amount cited | Up to $365 million raised since January 2025 | $135 million for the round |
| Field | Asthma, COPD, atopic dermatitis | Cancer immunotherapy (Lynch syndrome) |
| Most advanced stage | Phase 2/3 (POLARIS-1) | Registrational trial upcoming for NOUS-209 |
| Published valuation | No | No |
In both cases, the amount is public but the valuation is not. Our benchmarks on the startup term sheet show that this is the rule for recent Swiss announcements. For an order of magnitude, CB Insights puts the average global round at $49.8 million in 2026. In 2021, Swiss start-ups received a record CHF 3.1 billion in venture capital. Other cases can be found in our section on startup fundraising.
What we don't know yet
- The amount targeted by the offering, the number of shares and the price range: the filing does not publish them.
- The date of the first listing: no timetable has been given.
- The reason for choosing Nasdaq rather than the Swiss stock exchange: the company does not explain it. All that is known is that its main investors are global healthcare funds and that WIN027 has open trial applications in the United States.
- Windward Bio's valuation and the breakdown of the 365 million between its rounds.
For a saver in Switzerland, there is therefore nothing to buy at this stage. What happens next will depend on the terms of the offering, once they are published.
