By Adriano Marchese

Upstream Bio said a Phase 2 clinical trial for its respiratory-disease treatment met its primary endpoint in two dosing regimens, but that a third treatment group didn't see consistent improvements.

The clinical-stage biotechnology company said the Phase 2 Valiant clinical trial, evaluating verekitug in adults with severe asthma, showed that verekitug reduced asthma attacks and improved lung function with dosing of 100 milligrams every 12 weeks and 400 mg every 24 weeks.

For another low-dose treatment group, 100 milligrams every 24 weeks, Upstream said there were positive effects but not consistent improvements toward the trials' endpoints.

Shares were down about 22% to $21.83 in premarket trading.

Asthma is a chronic condition in which the airways become inflamed and narrowed, making it hard to breathe.

Upstream said it will now use the data collected from the previous trials to inform its decisions for the following phase 3 trial, for which it says planning has already begun.

Write to Adriano Marchese at adriano.marchese@wsj.com

(END) Dow Jones Newswires

February 11, 2026 08:12 ET (13:12 GMT)

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