Vial Doses First Patient with Asthma in Phase 1b Study of Vial's IL-13 x TSLP, a Bispecific Antibody Designed for Twice-Yearly Dosing

• Vial's IL-13 x TSLP is designed to deliver breadth, depth, and durability of Type 2 disease control in a single half-life-extended antibody
• Phase 1a data in healthy volunteers (15–800 mg IV) support progression into patients, with pharmacokinetics that could support twice-yearly (Q6M) dosing
• Phase 1b study will evaluate safety, tolerability, pharmacokinetics, and FeNO-based proof-of-mechanism in patients with mild-to-moderate asthma
• Interim Phase 1b data readout expected in H1 2027

SAN FRANCISCO, Oct. 5, 2026 /PRNewswire/ -- Vial, a clinical-stage biotechnology company, today announced that it has dosed the first patient in its Phase 1b clinical study of Vial's IL-13 x TSLP in patients with mild-to-moderate asthma. Vial's IL-13 x TSLP is a novel, half-life-extended bispecific antibody in development for the treatment of asthma and other atopic and inflammatory diseases.

The Phase 1b study follows completion of five single ascending dose cohorts in healthy adult volunteers at doses from 15 mg to 800 mg IV. In those cohorts, Vial's IL-13 x TSLP was generally well tolerated at all dose levels and showed an extended pharmacokinetic profile with the potential to support ultra-long-acting dosing.

"Moving into patients is the defining step for Vial's IL-13 x TSLP program. Our Phase 1a data in healthy volunteers showed the safety and pharmacokinetic profile the program was designed to meet. We now intend to show that dual IL-13 and TSLP blockade, delivered with an ultra-long-acting dosing interval, can meaningfully improve asthma biomarkers, namely FeNO and FEV1, in patients living with asthma. We look forward to sharing these data as the program progresses," said Simon Burns, CEO of Vial.

About Vial's IL-13 x TSLP Phase 1b Study

The IL-13 x TSLP Phase 1b study is a randomized, double-blind, placebo-controlled study in adults with mild-to-moderate asthma. The primary endpoint is safety and tolerability. Secondary and exploratory endpoints include pharmacokinetics, immunogenicity, change from baseline in FeNO, lung function (FEV1), and pharmacodynamic biomarkers of Type 2 inflammation, including TARC (CCL17) and blood eosinophils. Data from this study are expected to inform dose and dosing-interval selection, as well as future development in other atopic and inflammatory diseases.

About Vial's IL-13 x TSLP Bispecific Antibody Program

Vial's IL-13 x TSLP is a novel IgG1-based bispecific antibody targeting IL-13 and TSLP to address both the initiation and effector arms of Type 2 inflammation. It incorporates half-life extension engineering intended to enable twice-yearly dosing. Preclinical data support a potentially best-in-class profile characterized by picomolar dual-target binding, potent inhibition of Type 2 signaling including CCL17 secretion, and favorable developability characteristics supporting an extended dosing interval. The program is initially being developed for asthma, with potential for indication expansion into other atopic and inflammatory diseases.

About Vial

Vial is a clinical-stage biotechnology company based in San Francisco. Vial is focused on addressing unmet need in Immunology & Inflammation by developing potentially best-in-class biologics. Founded in 2020, Vial brings together a multidisciplinary team spanning R&D, Clinical Development, Clinical Operations, Engineering, Product, and Design. For more information, please visit www.vial.com.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of applicable securities laws. These statements include, but are not limited to, statements regarding: the design, conduct, enrollment, and timing of the Phase 1b study; the therapeutic potential of Vial's IL-13 x TSLP program; projected dosing intervals, including the potential for twice-yearly dosing; expected data readout timelines; and plans for future clinical development. These statements involve risks and uncertainties, and actual results may differ materially from those expressed or implied. Factors that could cause differences include: unexpected safety or efficacy results observed during clinical studies; the possibility that results from preclinical studies or earlier clinical trials may not be predictive of future results; changes in regulatory requirements; the ability to enroll patients on the expected timeline; and general clinical development risks. Vial undertakes no obligation to update forward-looking statements to reflect events or circumstances arising after the date of this release, except as required by law.

Contact:
Simon Burns, Chief Executive Officer
[email protected]

For Media:
[email protected]

SOURCE Vial