Windward Bio, a Basel, Switzerland-based clinical-stage biotechnology company developing long-acting antibodies for serious immunological conditions, has raised $165M in crossover financing led by OrbiMed. The round funds advancement of its pipeline, including WIN378, an ultra long-acting anti-TSLP monoclonal antibody with potential twice-yearly dosing for asthma, and WIN027, a TSLP x IL-13 bispecific antibody. This brings total funding to $365M since its January 2025 launch with a $200M Series A.
Swiss Private Funding Reaches Record Highs
The timing aligns with a surge in Swiss biotech private investments, which hit a record CHF 1.15B in 2026, up 38% year-over-year per the Swiss Biotech Report. Windward's crossover round, closed in May 2026, exemplifies this momentum amid a broader rebound in immunology funding. New participants like RA Capital Management and Sanofi Ventures join existing backers Novo Holdings and RTW Investments, signaling conviction in long-acting formats.
Monthly Dosing Hinders Patient Adherence
Current anti-TSLP therapies like Tezspire from Amgen and AstraZeneca require monthly subcutaneous injections, limiting adherence in severe asthma and COPD patients. The asthma biologics market stands at $10.05B in 2026, growing to $17.92B by 2031 at 12.27% CAGR, driven by demand for targeted therapies. Yet, frequent dosing remains a key barrier, with trends shifting toward long-acting and bispecific options.
Engineering Half-Life for Twice-Yearly Dosing
Windward's WIN378, licensed from Kelun-Biotech and Harbour BioMed, features half-life extension technology enabling potential twice-yearly subcutaneous administration, low anti-drug antibodies, and Phase 1 safety. Now in a global Phase 2/3 Polaris trial for asthma with readouts in H2 2026, it plans Phase 2 in COPD by mid-2026. WIN027, in-licensed from Qyuns Therapeutics, targets TSLP and IL-13 in Phase 1 with proof-of-concept studies slated for Q4 2026 across respiratory and dermatological indications.
Bispecifics Expand Beyond Monotherapy
Unlike single-target competitors, WIN027's bispecific design addresses multiple pathways, mirroring emerging trends like Sanofi's lunsekimig. Upstream Bio's verekitug, with over $400M in equity funding, showed Tezspire-like efficacy at quarterly dosing but weaker results at six months in Phase 2. Windward positions its ultra-long-acting profile as best-in-disease, aiming to disrupt the standard.
Tier-1 Syndicate Eyes Pre-IPO Path
OrbiMed, managing $20B AUM with a track record in immunology like Mirador Therapeutics, led the round with partners RA Capital and corporate VC Sanofi Ventures. Sanofi's involvement validates adjacency to its Dupixent franchise in IL-4/13 respiratory immunology. This elite syndicate, including Janus Henderson and follow-ons from Series A, extends runway through multiple 2026 readouts, positioning Windward for Phase 3 or IPO.
TSLP Space Crowds With Long-Acting Bets
The TSLP inhibitor market heats up post-Tezspire approval, with Uniquity Bio securing $300M from Blackstone for solrikitug in Phase 2 asthma/COPD. GSK's depemokimab nears EU approval with ultra-long-acting claims, while Upstream's recent data highlights dosing challenges. Windward's $365M war chest funds differentiation in this $10B+ asthma biologics arena growing at double digits.
Ex-Roche Leader Drives Rapid Progress
CEO Luca Santarelli, previously leading Roche spinouts VectivBio (acquired by Ironwood) and Therachon (Pfizer), launched Windward in January 2025. His track record in rare disease exits and immunology platforms brings proven execution to the team. Headquartered in Basel, the leadership leverages Swiss biotech ecosystem strengths.
Pipeline Milestones Define 2026 Roadmap
The financing supports Polaris Phase 2/3 asthma readout in H2 2026, Phase 3 initiation Q4 2026, COPD Phase 2 by June 2026, and WIN027 POC studies Q4 2026. With deployments toward late-stage trials, Windward targets national and global expansion in respiratory and dermatology markets.
As CEO Luca Santarelli noted:
"This financing further strengthens our balance sheet and allows us to advance our programs of next-generation therapies for patients living with serious respiratory and dermatological diseases."