Upstream Bio, Inc.
Upstream Bio, Inc. (Nasdaq: UPB) is a clinical-stage biotechnology company developing treatments for inflammatory diseases, initially focused on severe respiratory disorders. Its sole product candidate, verekitug, is a monoclonal antibody that targets and inhibits the thymic stromal lymphopoietin (TSLP) receptor. The… From the company’s description.
In fiscal 2025, Upstream Bio, Inc. reported revenue of $2.85M, up 20.4% from fiscal 2024, and a net loss of $143.44M. Operations used $133.28M in cash. Over the twelve months to Jun 30, 2026, revenue was $3.16M.
Margins and return on equity change in ; everything else in percent. Fewer shares and less debt are shown plainly, not as bad news — it depends what you make of buybacks. Dotted labels explain each measure. is shown separately from the annual figures.
What Upstream Bio, Inc. does
In the company’s own words
Upstream Bio, Inc. (Nasdaq: UPB) is a clinical-stage biotechnology company developing treatments for inflammatory diseases, initially focused on severe respiratory disorders. Its sole product candidate, verekitug, is a monoclonal antibody that targets and inhibits the thymic stromal lymphopoietin (TSLP) receptor. The company is evaluating verekitug for severe asthma, chronic rhinosinusitis with nasal polyps (CRSwNP), and chronic obstructive pulmonary disease (COPD); its development program includes Phase 2 trials in all three indications and planned Phase 3 trials in severe asthma and CRSwNP. Upstream has one development program and does not report business segments. It acquired verekitug from Astellas Pharma in 2021, which had discovered the compound and completed preclinical work and an initial Phase 1 study. Upstream’s clinical development is intended to address patients with inflammatory diseases, with future potential in other TSLP-driven conditions. Its website is https://upstreambio.com.
Company details
- Sector
- Health Care
- Industry (SIC)
- Pharmaceutical Preparations
- Headquarters
- WALTHAM, MA
- Fiscal year end
- December
- CIK
- 2022626
- SIC
- 2834
Financial performance, year by year
Fiscal 2024–2025 · USDThe full income statement, balance sheet and cash flow for each of these years — every figure traceable to its filing — is on the Financials tab with a free account.
Who owns Upstream Bio, Inc. — and what changed
Funds as of 2026Q2 · superinvestors as of 2026-06-30
Largest fund holders · Upstream Bio, Inc.’s weight in each
Fund ownership is a floor, not a census — pensions, insurers and people holding shares directly are not visible here.
Fund ownership counts N-PORT filers only, so it is a floor rather than a census — pensions, insurers and direct holders are not visible here, and the remainder is not “held by individuals”.
Could not be determined for this company: bond issues.
Every fund and institutional holder, quarter by quarter, is on the Ownership tab with a free account.
Recent filings
All filings →Each filing opens into its own statements and disclosures here.
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