secwatch.observer — SEC 8-K summary
======================================

Issuer:     Upstream Bio, Inc. (UPB)
CIK:        0002022626
Form:       8-K
Filed at:   2025-09-02T23:59:59+00:00
Accession:  0002022626-25-000005
Event type: other_material
Sentiment:  positive
Materiality: 0.78
Item codes: 7.01, 8.01, 9.01
LLM model:  deepseek-v4-flash:cloud@v2

Upstream Bio Phase 2 VIBRANT trial meets primary endpoint for verekitug in CRSwNP
--------------------------------------------------------------------------------

- Placebo-adjusted reduction in nasal polyp score of -1.8 (p<0.0001) at Week 24; key secondary endpoint nasal congestion score reduced -0.8 (p=0.0003).
- 76% reduction in need for surgery or systemic corticosteroids (p=0.03); no serious adverse events observed.
- Verekitug (100 mg every 12 weeks) generally well tolerated; company plans to engage regulators and present at upcoming medical conference.
- Additional top-line data for verekitug in severe asthma expected in coming months.

Source:
  EDGAR index:    https://www.sec.gov/Archives/edgar/data/2022626/000202262625000005/0002022626-25-000005-index.htm
  Primary doc:    https://www.sec.gov/Archives/edgar/data/2022626/000202262625000005/upb-20250902.htm
  HTML page:      https://secwatch.observer/filing/0002022626-25-000005

License: Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer