Upstream Bio, Inc.
Business
Upstream Bio is a clinical-stage biotechnology company developing verekitug, a monoclonal antibody antagonist of the TSLP receptor for treating inflammatory diseases. The company is advancing verekitug through Phase 2 trials in severe asthma, chronic rhinosinusitis with nasal polyps, and chronic obstructive pulmonary disease. Verekitug targets TSLP signaling upstream of other approved biologics, enabling extended dosing intervals of up to 24 weeks compared to competitor four-week dosing.
Summary from 10-K filed 2026-03-26
Financials
Consolidated Statement of Income
| Concept | Trend | FY 2025 2025-12-31 | FY 2024 2024-12-31 | FY 2023 2023-12-31 |
|---|---|---|---|---|
| Collaboration revenue | 3 | 2 | 2 | |
| Research and development | 137 | 63 | 32 | |
| General and administrative | 26 | 17 | 11 | |
| Total operating expenses | 163 | 80 | 42 | |
| Loss from operations | −160 | −78 | −40 | |
| Change in fair value of preferred stock tranche right liability | 0 | 3 | 16 | |
| Interest income | 17 | 12 | 4 | |
| Other expense, net | −15,000 | −24,000 | −115,000 | |
| Total other income, net | 17 | 15 | 20 | |
| Net loss | −143 | −63 | −21 | |
| Redeemable convertible preferred stock cumulative dividends | 0 | −14 | −18 | |
| Net loss attributable to common stockholders | −143 | −76 | −38 | |
| Net loss per share attributable to common stockholders, basic | −2.66 | −5.58 | −12.95 | |
| Net loss per share attributable to common stockholders, diluted | −2.66 | −5.58 | −12.95 | |
| Weighted-average common shares outstanding, basic | 54 | 14 | 3 | |
| Weighted-average common shares outstanding, diluted | 54 | 14 | 3 | |
| Unrealized gain (loss) on investments, net of tax | 555,000 | −46,000 | 21,000 | |
| Total other comprehensive income (loss) | 555,000 | −46,000 | 21,000 | |
| Comprehensive loss | −143 | −63 | −21 |
Consolidated Balance Sheet
| Concept | Trend | FY 2025 2025-12-31 | FY 2024 2024-12-31 | FY 2023 2023-12-31 | FY 2022 2022-12-31 |
|---|---|---|---|---|---|
| Cash and cash equivalents | 102 | 326 | 26 | — | |
| Short-term investments | 240 | 145 | 84 | — | |
| Accounts receivable | 668,000 | 613,000 | 98,000 | — | |
| Prepaid expenses and other current assets | 10 | 8 | 7 | — | |
| Total current assets | 352 | 479 | 117 | — | |
| Property and equipment, net | 559,000 | 582,000 | 159,000 | — | |
| Operating lease right-of-use assets | 1 | 2 | 43,000 | — | |
| Restricted cash | 194,000 | 194,000 | — | — | |
| Total assets | 354 | 482 | 117 | — | |
| Accounts payable | 3 | 4 | 2 | — | |
| Accrued expenses and other current liabilities | 10 | 6 | 4 | — | |
| Operating lease liabilities, current portion | 720,000 | 704,000 | 45,000 | — | |
| Total current liabilities | 13 | 11 | 7 | — | |
| Operating lease liabilities, net of current portion | 549,000 | 1 | — | — | |
| Total liabilities | 14 | 12 | 9 | — | |
| Commitments and contingencies (Note 13) | — | — | — | — | |
| Preferred stock, $0.001 par value; 10,000,000 shares authorized at December 31, 2025 and December 31, 2024; no shares issued and outstanding at December 31, 2025 and December 31, 2024 | — | — | — | — | |
| Common stock, $0.001 par value; 500,000,000 shares authorized at December 31, 2025 and December 31, 2024; 54,237,750 and 53,603,398 shares issued and outstanding at December 31, 2025 and December 31, 2024, respectively | 54,000 | 53,000 | 3,000 | — | |
| Additional paid-in capital | 673 | 661 | 5 | — | |
| Accumulated other comprehensive income (loss) | 530,000 | −25,000 | 21,000 | — | |
| Accumulated deficit | −334 | −191 | −128 | — | |
| Total stockholders' equity | 340 | 470 | −123 | −106 | |
| Total liabilities and stockholders' equity | 354 | 482 | 117 | — |
Consolidated Statement of Cash Flows
| Concept | Trend | FY 2025 2025-12-31 | FY 2024 2024-12-31 | FY 2023 2023-12-31 |
|---|---|---|---|---|
| Net loss | −143 | −63 | −21 | |
| Depreciation and amortization expense | 200,000 | 89,000 | 60,000 | |
| Stock-based compensation expense | 10 | 6 | 3 | |
| Net amortization of premiums and accretion of discounts on short-term investments | −2 | −2 | −1 | |
| Non-cash lease expense | 561,000 | 182,000 | 82,000 | |
| Accounts receivable | −55,000 | −515,000 | 314,000 | |
| Prepaid expenses and other assets | −2 | −1 | −6 | |
| Accounts payable | −1 | 2 | 1 | |
| Accrued expenses and other current liabilities | 4 | 2 | 422,000 | |
| Operating lease liabilities | −565,000 | −133,000 | −82,000 | |
| Net cash used in operating activities | −133 | −59 | −38 | |
| Purchases of short-term investments | −386 | −291 | −129 | |
| Maturities of short-term investments | 293 | 232 | 46 | |
| Purchases of equipment | −165,000 | −511,000 | −144,000 | |
| Net cash used in investing activities | −93 | −59 | −83 | |
| Proceeds from the issuance of Series B redeemable convertible preferred stock, net of issuance costs paid | 0 | 150 | — | |
| Proceeds from initial public offering, net of underwriters discounts and commissions | 0 | 273 | — | |
| Payments of initial public offering costs | −34,000 | −4 | — | |
| Proceeds from exercises of stock options | 2 | 159,000 | 118,000 | |
| Proceeds from issuance of common stock under employee stock purchase plan | 196,000 | 0 | — | |
| Net cash provided by financing activities | 2 | 419 | 130 | |
| Net increase (decrease) in cash, cash equivalents and restricted cash | −224 | 300 | 9 | |
| Right-of-use asset obtained in exchange for operating lease liability | 0 | 2 | 36,000 | |
| Initial public offering costs included in accounts payable | 0 | 34,000 | — |
Filings
Material Events
Insiders
Institutional Holders
Frequently asked questions
What is Upstream Bio, Inc.'s CIK number?
Upstream Bio, Inc.'s SEC CIK number is 0002022626 (2022626). The CIK (Central Index Key) is the permanent identifier the SEC assigns to every EDGAR filer — unlike a ticker symbol, it never changes.
Where can I find Upstream Bio, Inc.'s SEC filings?
All of Upstream Bio, Inc.'s EDGAR filings — 10-K annual reports, 10-Q quarterly reports, 8-K material events, and insider transactions — are listed on this page, sourced live from SEC EDGAR.
When did Upstream Bio, Inc. last report earnings?
Upstream Bio, Inc. (UPB) most recently filed an earnings 8-K with the SEC on May 13, 2026, furnishing its results under Item 2.02 (Results of Operations and Financial Condition). The earnings press release is attached to that filing (accession 0001193125-26-220578). This is Upstream Bio, Inc.'s most recent earnings filing of record — not a forecast of its next earnings date.
What is Upstream Bio, Inc.'s most recent earnings 8-K?
Upstream Bio, Inc.'s latest earnings 8-K (Item 2.02) was filed May 13, 2026 under accession 0001193125-26-220578. It carries the quarterly or annual earnings press release — the earliest official, SEC-filed version of the results.
View Upstream Bio, Inc.'s latest earnings 8-K →
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