Upstream Bio has announced the commencement of patient dosing in its Phase II VALIANT clinical trial of verekitug (UPB-101) for severe asthma.

The recombinant fully human immunoglobulin G1 monoclonal antibody blocks the thymic stromal lymphopoietin receptor (TLSPR) to inhibit TSLP-driven inflammation.

The randomised, double-blind, placebo-controlled VALIANT trial is designed to assess the efficacy of verekitug in severe asthma through a 24-week dosing regimen, aiming to establish its potential as a best-in-class treatment.

Patients will receive either 100mg and 400mg of verekitug every 24 weeks, 100mg every 12 weeks, or a placebo.

The primary endpoint is the annual asthma exacerbation rate (AAER).

In a Phase II trial, verekitug is being studied for patients with chronic rhinosinusitis with nasal polyps (CRSwNP).

Upstream Bio CEO Sam Truex said: “Verekitug has the potential to be a best-in-class inhibitor of TSLP signaling based on its swift, substantial and sustained effect on clinically relevant biomarkers that are known to correlate with impact on AAER.

“Our team is thrilled to carry our momentum from Phase Ib into our global Phase II studies where we intend to demonstrate how verekitug’s high potency translates to clinical outcomes that will benefit patients with many types of asthma.”

Verekitug has shown promise in preclinical studies.

Its safety and tolerability have been confirmed in three Phase I studies. A Phase Ib study revealed that the antibody maintained maximal inhibition of disease-related biomarkers in asthma patients for 24 weeks post-dose.

Upstream Bio chief medical officer and R&D head Aaron Deykin said: “We are thrilled to initiate the Phase II study in severe asthma after the findings from our multiple ascending dose (MAD) study in asthma patients demonstrated that verekitug produces a compelling reduction in disease-related biomarkers.”