Catalyst Calendar

Tue, Sep 8, 2026

1 updates

3:30 AM

Upstream Bio Presents Results from the Phase 2 VALIANT Trial of Verekitug for the Treatment of Severe Asthma in Oral Presentation at ERS Congress 2026

– Verekitug, 100 mg dosed every 12 weeks, reduced AAER by 56% compared to placebo in patients with severe asthma – – Verekitug also delivered clinically meaningful improvements in lung function (FEV 1) and exhaled nitric oxide (FeNO) with every 12-week dosing – – The Company remains on track to

Presentation / Abstract • Phase 2ERS oral presentation Tue, Sep 8, 2026upstreambio.com

Tue, Sep 1, 2026

1 updates

UPB

7:00 AM

Upstream Bio Announces Pivotal Phase 3 Development Plans for Verekitug in Both Severe Asthma and CRSwNP

– Following productive FDA discussions, Upstream Bio will study 400 mg of verekitug administered every 12 weeks, versus placebo, in severe asthma and CRSwNP with one pivotal Phase 3 trial in each indication – – The Company’s Phase 3 strategy is designed to deliver best-in-class efficacy across both

upstreambio.com

Tue, Aug 11, 2026

1 updates

UPB

7:00 AM

Upstream Bio Reports Second Quarter 2026 Financial Results and Highlights Continued Progress

– Company rapidly advancing toward Q1 2027 initiation of Phase 3 trials designed to deliver best-in-class efficacy with convenient quarterly dosing in both severe asthma and CRSwNP; End-of-Phase 2 interactions with FDA on track – – Completed enrollment in Phase 2 trial in COPD; data expected in the

Enrollment • Phase 2Enrollment milestone Tue, Jun 30, 2026upstreambio.com