Upstream Bio (UPB) investor relations material

Company overview and strategy

• Clinical-stage immunology company developing verekitug, a potent TSLP receptor antagonist for severe respiratory diseases.

• Completed Phase 2 trials in severe asthma and CRSWNP; ongoing Phase 2 in COPD with data expected H2 2027.

• Phase 3 trials in severe asthma and CRSWNP planned for Q1 2027, following FDA engagement in mid-2026.

• Targeting best-in-class efficacy with a single quarterly at-home injection for broad patient populations.

• Existing capital expected to fund operations through 2027.

Market opportunity

• Severe asthma and COPD projected to drive a $35B+ global biologics market by 2033.

• Severe asthma biologics market expected to grow from $7.5B in 2023 to $12.6B in 2032.

• CRSWNP biologics sales estimated at $1.5B+ annually, with tezepelumab projected to exceed $600M by early 2030s.

• COPD biologics market projected at $23B by 2033, with tezepelumab potentially reaching $5B if approved.

• Less than 25% of eligible severe asthma patients currently receive biologic therapies.

Verekitug clinical profile and differentiation

• Verekitug is a fully human IgG1 antibody with ~300-fold greater potency than tezepelumab.

• Demonstrated robust efficacy and favorable safety in ~500 participants across Phase 1 and 2 trials.

• Phase 2 trials showed efficacy meeting or exceeding approved biologics in severe asthma and CRSWNP with 100 mg every 12 weeks.

• Positive treatment effects observed in both high and low eosinophil subgroups.

• Well-characterized immunogenicity profile with no meaningful impact on safety or efficacy.