Windward Bio catches $175m from its IPO

Swiss biotech Windward Bio has raised $175 million in its Nasdaq IPO as it prepares to take on some heavyweight rivals with its TSLP-acting drug for inflammatory respiratory and dermatological diseases.

Basel-based Windward – which has been backed by Novo Holdings – sold around 10.3 million shares for $17 apiece in the listing, in the middle of its anticipated range, and is due to start trading on the Nasdaq later today under the WWB ticker. It is also planning to raise another $50 million in a concurrent private placement with Sanofi.

Windward is developing a long-acting TSLP inhibitor, WIN378, which is licensed from China's Kelun-Biotech and has the potential to be dosed just twice a year. If it reaches the market, it would compete with Amgen and AstraZeneca's first-to-market TSLP inhibitor Tezspire (tezepelumab), which needs to be dosed once every four weeks.

Tezspire launched in 2022 as an add-on maintenance treatment for severe asthma in patients aged 12 and older – the first biologic for the respiratory disorder without phenotype or biomarker restrictions – and has since also been cleared in a prefilled pen injector formulation and for chronic rhinosinusitis with nasal polyps (CRSwNP). It has grown strongly since launch, reaching almost $1.9 billion in the first nine months of this year, a rise of 42%.

WIN378 is in the phase 2/3 POLARIS-1 trial in severe uncontrolled asthma, with interim results from the phase 2 portion reported in September and the full readout expected in the first half of 2027, as well as a phase 2 trial in chronic obstructive pulmonary disease (COPD). Tezspire, meanwhile, is also in mid-stage testing for COPD.

Two twice-yearly doses have been selected for the phase 3 portion of POLARIS-1, which is will look at the effect of WIN378 on annualised asthma exacerbation rate in patients with severe asthma.

Windward is also working on a second candidate, codenamed WIN027 and licensed from China's Qyuns Therapeutics, which is a bispecific antibody targeting both TSLP and IL-13 that is in phase 1 testing, with phase 2 trials in COPD and atopic dermatitis due to start enrolling in the first half of 2027.

WIN027 shares the mechanism of some other experimental therapies, including Sanofi's lunsekimig, which has shown efficacy in phase 2 testing for asthma and CRSwNP, but missed the mark in atopic dermatitis. Sanofi has pushed lunsekimig into late-stage trials, including the phase 2b/3 PERSEPHONE and THESEUS trials in COPD and the phase 2b AIRLYMPUS trial in high-risk asthma.

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