secwatch.observer — SEC 8-K summary
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Issuer:     Upstream Bio, Inc. (UPB)
CIK:        0002022626
Form:       8-K
Filed at:   2026-02-11T23:59:59+00:00
Accession:  0001193125-26-045500
Event type: other_material
Sentiment:  positive
Materiality: 0.80
Item codes: 7.01, 8.01, 9.01
LLM model:  deepseek-v4-flash:cloud@v2

Upstream Bio reports positive Phase 2 VALIANT results: verekitug reduces asthma exacerbations by 56% and 39%
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- Verekitug 100 mg q12w reduced AAER by 56% (p<0.0003); 400 mg q24w reduced AAER by 39% (p<0.02) vs placebo.
- Placebo-adjusted FEV1 improvement of 122 mL (q12w) and 139 mL (q24w) at week 60.
- FeNO suppressed vs placebo by 20.4 ppb (q12w) and 26.3 ppb (q24w); mean reductions of 43-45% from baseline.
- Verekitug well tolerated with safety consistent with prior studies; >90% of eligible patients rolled over to VALOUR LTE.
- Company plans to advance verekitug into Phase 3 trials in severe asthma and CRSwNP after regulatory interactions.

Source:
  EDGAR index:    https://www.sec.gov/Archives/edgar/data/2022626/000119312526045500/0001193125-26-045500-index.htm
  Primary doc:    https://www.sec.gov/Archives/edgar/data/2022626/000119312526045500/d44802d8k.htm
  HTML page:      https://secwatch.observer/filing/0001193125-26-045500

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