Windward Bio raises $165M to advance long-acting immunology drugs
What's the deal? Windward Bio, a clinical-stage biotech company, has closed an upsized $165 million crossover financing round to push its pipeline of long-acting immunology therapies toward late-stage trials. OrbiMed led the round, with participation from RA Capital Management, Janus Henderson Investors, Sanofi Ventures, and existing investors including Novo Holdings, Blue Owl Healthcare Opportunities, SR One, Omega Funds, and RTW Investments.
The proceeds will advance lead candidate WIN378 — a potential first-to-market, ultra long-acting anti-TSLP antibody with twice-yearly dosing — into Phase 3 trials by Q4 2026. A second asset, WIN027, a bispecific antibody targeting both TSLP and IL-13, will enter proof-of-concept studies across respiratory and dermatology indications on the same timeline.
Why now? Windward Bio has moved fast since launching in January 2025, in-licensing two clinical-stage assets and raising $365 million in total. Its Phase 2 dose-ranging study of WIN378 in asthma is fully enrolled, with initial data expected in the second half of 2026. A Phase 2 study in chronic obstructive pulmonary disease (COPD) is set to begin in Q2 2026.
WIN027's Phase 1 data readout is also expected by end of 2026, giving the company a string of catalysts that make this the right moment to extend its cash runway and lock in crossover investors ahead of a potential IPO.
What could go wrong? The anti-TSLP space is increasingly crowded, with AmgenDealroom has a profile for this one. Try Dealroom →'s Tezspire already on the market. Windward's bet rests on differentiation through dosing convenience — twice-yearly injections versus monthly — but clinical data still needs to prove comparable or superior efficacy. Any setback in the Phase 2/3 POLARIS programme or the Phase 1 bispecific study could undermine the company's timeline and valuation.
Crossover rounds also signal IPO ambitions, and a volatile public market could complicate that path.
The signal: Windward Bio's ability to raise $365 million in total within roughly 18 months of launch — reaching late growth stage on Dealroom — illustrates how quickly in-licensing clinical assets and pairing them with a compelling dosing narrative can attract heavyweight capital. OrbiMed leading the crossover, alongside public-market funds such as RA Capital Management and Janus Henderson Investors, points to strong crossover investor conviction that the ultra long-acting anti-TSLP category can compete with Amgen's established Tezspire franchise on convenience alone, provided the Phase 2 data hold up.
Read more: novoholdings.dk
