Windward Bio
Basel NewCo developing a twice-yearly anti-TSLP antibody co-licensed from Harbour BioMed and Kelun-Biotech.
1. Core Product / Service
Windward Bio (Basel, with US operations; founded 2024, launched 2025-01-10) holds global rights, excluding Greater China and several Southeast and West Asian countries, to WIN378 — the antibody known as HBM9378 at Harbour BioMed and SKB378 at Kelun-Biotech [1][3]. WIN378 is a fully human, effector-silenced anti-TSLP antibody engineered for long half-life; the company says it is the only known TSLP blocker that binds two different sites on TSLP [3].
In the Phase 2 part of the global Phase 2/3 POLARIS-1 asthma study (147 patients enrolled; interim analysis on the first 98), a single dose gave placebo-adjusted FEV1 gains of up to 256 mL (p=0.033), FeNO reductions of up to 43% and blood-eosinophil reductions of up to 51% at Week 24, with a half-life of up to 75 days, consistent with twice-yearly dosing [3]. The Phase 3 part of POLARIS-1 has started; POLARIS-2 is planned for 1H 2027, and a Phase 2 COPD study (SIRIUS) is running [3]. A second program, WIN027, is a TSLP×IL-13 bispecific [3].
2. Target Users & Pain Points
- Patients / payers: moderate-to-severe asthma and COPD; current anti-TSLP therapy (tezepelumab) is dosed every four weeks, so a twice-yearly shot targets adherence and convenience [3].
- Licensors: two Chinese biotechs that co-own one asset split a single Western development partner instead of each running global trials.
3. Competitive Landscape
| Player | Asset | Dosing / stage |
|---|---|---|
| Amgen / AstraZeneca | Tezepelumab (Tezspire) | Approved, every 4 weeks |
| generate-biomedicines | GB-0895 (AI-designed anti-TSLP) | Phase 3; long-acting |
| GSK | Depemokimab (anti-IL-5) | Twice-yearly benchmark in asthma |
| Windward | WIN378 | Phase 3 started 2026 |
4. Unique Observations
- Crowded "ultra-long-acting TSLP" lane. WIN378 competes directly with Generate's AI-designed GB-0895, also pitched on extended dosing — a direct match-up between a China-originated molecule and an AI-designed one in the same indication.
- Wet lab stays with the originators. The antibody was discovered and taken through China Phase 1 by Harbour BioMed and Kelun-Biotech; Windward entered at the "Phase 2-ready" point and runs global trials [1][4]. No manufacturing facility or supply agreement has been disclosed, so who supplies clinical material for POLARIS is not public.
- Equity, not just cash, to the licensors. The near-term payment was paid partly in shares of Windward's parent company, split equally between the two licensors [2][4].
5. Financials / Funding
- Series A: $200M (January 2025), led by OrbiMed, Novo Holdings and Blue Owl [1][4].
- Licensor terms: $45M upfront + near-term milestone, paid in cash plus equity in Windward's parent, shared equally by Harbour BioMed and Kelun-Biotech; total deal value up to $970M [1][2]. Individual equity stakes have not been disclosed.
6. People & Relationships
- Founder, CEO and Board Chair: Luca Santarelli, M.D. [3].
- Licensors: Harbour BioMed (HKEX: 02142), Kelun-Biotech.
- Investors: OrbiMed, Novo Holdings, Blue Owl [1].
- Competitor: generate-biomedicines.
- Peer NewCos: kailera-therapeutics, braveheart-bio, candid-therapeutics, verdiva-bio, timberlyne-therapeutics, sentivera.
Sources
- [1] Fierce Biotech, "Novo Holdings-backed Windward generates $200M Series A, inks $970M biobucks deal" (accessed 2026-10-14)
- [2] Contract Pharma, "Harbour BioMed, Kelun-Biotech license TSLP antibody to Windward Bio" (accessed 2026-10-14)
- [3] Windward Bio press release, positive Phase 2 POLARIS-1 results, 2026-09-08 (accessed 2026-10-14)
- [4] Research notes on China-asset NewCos, 2026-10-14