Here are the 10-K annual reports from Upstream Bio, Inc. (UPB) in our archive since June 2025, newest first, and each one links through to the document itself with the summary and the scores our analysis gives it.
A 10-K covers the audited annual report, with the full financial statements, so if you follow UPB and want that one kind of document rather than the whole filing history, this is the page to keep. The company's other filings, of every form, are on the full UPB filings page.
Upstream Bio, Inc. is a clinical-stage biotechnology company focused on inflammatory diseases, initially severe respiratory disorders. Its lead and only product candidate, verekitug, is a fully human monoclonal antibody that blocks the receptor for thymic stromal lymphopoietin (TSLP), a key upstream driver of inflammation.
Verekitug has shown high TSLP receptor occupancy, a favorable safety profile and strong, sustained reductions in asthma biomarkers (eosinophils and FeNO) for up to 24 weeks after dosing in early trials, supporting extended dosing intervals. The company has completed Phase 2 studies in severe asthma and chronic rhinosinusitis with nasal polyps with positive top-line results, and has initiated a Phase 2 trial in COPD and a long-term asthma extension study.
Upstream Bio plans to start Phase 3 trials in severe asthma and CRSwNP in the first quarter of 2027, aiming for high efficacy without biomarker restrictions and quarterly at-home administration. Management sees broader potential for verekitug across multiple TSLP-driven diseases beyond its initial respiratory indications.