Recent 8-K filings for UPB

• September 1, 2026, 7:05 AM ET other material materiality 0.80 positive item 7.01item 8.01item 9.01

  Upstream Bio announces Phase 3 plans for verekitug in severe asthma and CRSwNP

  Phase 3: 400mg verekitug SC every 12 weeks vs placebo; one trial each in severe asthma and CRSwNP.

• August 11, 2026, 7:05 AM ET earnings materiality 0.60 neutral item 2.02item 9.01

  Upstream Bio Q2 net loss $39.7M; cash $261.3M funds through 2027; Phase 3 on track

  Net loss of $39.7M for Q2 2026 vs $40.0M year ago; R&D spend $36.1M, G&A $7.1M.

• June 10, 2026, 4:05 PM ET other materiality 0.10 neutral item 5.07 ◈ Shareholder Votes ×2

  Upstream Bio stockholders elect H. Edward Fleming and Liam Ratcliffe as Class II directors at 2026 Annual Meeting

  Both director nominees elected with over 40M votes for; Fleming received 40,715,035 for, Ratcliffe 43,812,021 for.

• May 13, 2026, 7:05 AM ET earnings materiality 0.50 neutral item 2.02item 9.01 ◈ Earnings Releases

  Upstream Bio reports Q1 net loss $40.6M; Phase 3 plans on track for 2027

  Cash, cash equivalents and short-term investments $294.6M as of March 31, 2026; expected to fund operations through 2027.

• March 26, 2026, 7:59 PM ET other material materiality 0.80 positive item 2.02item 9.01 ◈ Earnings Releases

  Upstream Bio details Phase 3 strategy for verekitug; positive Phase 2 asthma and CRSwNP data

  Phase 3 development plan for verekitug: high-dose quarterly regimen (up to 400 mg q12w) in severe asthma and CRSwNP; initiation in Q1 2027.

• March 26, 2026, 7:59 PM ET other material materiality 0.60 neutral item 1.01item 9.01 ◈ Material Agreements

  Upstream Bio enters into $150M at-the-market offering agreement with Leerink Partners

  Company may sell up to $150M of common stock through Leerink Partners as sales agent.

• February 11, 2026, 6:59 PM ET other material materiality 0.80 positive item 7.01item 8.01item 9.01

  Upstream Bio reports positive Phase 2 VALIANT results: verekitug reduces asthma exacerbations by 56% and 39%

  Verekitug 100 mg q12w reduced AAER by 56% (p<0.0003); 400 mg q24w reduced AAER by 39% (p<0.02) vs placebo.

• February 11, 2026, 6:59 PM ET other material materiality 0.65 neutral item 2.02item 7.01item 9.01

  Upstream Bio reports preliminary cash of $341.5M; Phase 2 VALIANT top-line data released

  Preliminary unaudited cash, cash equivalents and short-term investments of $341.5M as of Dec 31, 2025.

• November 5, 2025, 6:59 PM ET earnings materiality 0.85 positive item 2.02item 9.01

  Upstream Bio Q3 loss $33.7M; VIBRANT Ph2 CRSwNP meets primary endpoint

  VIBRANT Ph2 met primary endpoint: placebo-adjusted NPS reduction of -1.8 (p<0.0001) at 24 weeks.

• September 2, 2025, 7:59 PM ET other material materiality 0.78 positive item 7.01item 8.01item 9.01

  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).

• August 6, 2025, 7:59 PM ET earnings materiality 0.70 neutral item 2.02item 9.01

  Upstream Bio Q2 net loss $40.0M; cash $393.6M; CRSwNP Phase 2 data on track for Q3 2025

  Net loss of $40.0M in Q2 2025 vs. $14.7M in Q2 2024; R&D expense rose to $37.9M from $14.1M.

• June 12, 2025, 7:59 PM ET other materiality 0.15 neutral item 5.07

  Upstream Bio shareholders elect two Class I directors, ratify PwC as auditor

  Erez Chimovits received 42,089,191 votes for, 241,430 withheld; Marcella Kuhlman Ruddy received 41,993,308 for, 337,313 withheld.

• May 6, 2025, 7:59 PM ET earnings materiality 0.75 neutral item 2.02item 9.01

  Upstream Bio Q1 net loss $27.3M; cash $431.4M; Phase 2 CRSwNP data on track for Q3 2025

  Net loss $27.3M in Q1 2025 vs $10.9M in Q1 2024; R&D expenses $25.8M (up $14.1M YoY).

• March 12, 2025, 7:59 PM ET other material materiality 0.55 neutral item 2.02item 9.01

  Upstream Bio posts Q4 net loss $21.2M; CRSwNP Ph2 enrollment complete; cash through 2027

  Net loss of $21.2M in Q4 2024 ($11.8M in Q4 2023); R&D expenses $21.8M vs $11.6M.

• November 7, 2024, 6:59 PM ET earnings materiality 0.60 neutral item 2.02item 9.01

  Upstream Bio Q3 net loss $16.0M; IPO raises $293M, extends cash runway through 2027

  Net loss of $16.0M in Q3 2024 vs $3.1M loss in Q3 2023, driven by higher R&D and G&A costs.

• October 15, 2024, 7:59 PM ET other material materiality 0.20 neutral item 5.03item 9.01 ◈ Governance Changes ×2

  Upstream Bio files amended charter and bylaws following IPO completion

  Authorizes 500M shares of common stock and 10M shares of undesignated preferred stock.

Earnings & guidance

Materiality & sentiment trend

Max materiality 0.85 · Median 0.62 · Most common event other_material

5 positive 0 negative 11 neutral

source · UPB on sec.gov