Welcome to our dedicated page for UpStream Bio SEC filings (Ticker: UPB), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
The Upstream Bio, Inc. (NASDAQ: UPB) SEC filings page on Stock Titan provides access to the company’s regulatory disclosures as it advances verekitug, a monoclonal antibody targeting the thymic stromal lymphopoietin (TSLP) receptor, through clinical development. As a clinical-stage biotechnology company, Upstream Bio uses SEC reports to communicate trial progress, financial results, and other material information relevant to shareholders.
Recent Form 8-K filings referenced by the company include announcements of quarterly financial results and business highlights, as well as the furnishing of press releases and presentations. For example, an 8-K dated August 6, 2025, furnished a press release summarizing second quarter financial results and updates on Phase 2 trials in CRSwNP, severe asthma, and COPD. Another 8-K dated November 5, 2025, furnished third quarter results and program progress, while an 8-K dated September 2, 2025, furnished the press release and presentation describing positive top-line data from the VIBRANT Phase 2 CRSwNP trial.
Through these filings, investors can see how Upstream Bio reports collaboration revenue, research and development expenses related to verekitug, general and administrative expenses, and net loss figures, as well as balance sheet items such as cash, cash equivalents, and short-term investments. The filings also describe the design and endpoints of key clinical trials when they are the subject of a furnished press release.
On Stock Titan, these documents are supplemented with AI-powered summaries that highlight the main points of each filing, helping readers quickly understand what changed in a given quarter or event filing. Users can review 8-Ks tied to clinical data releases, financial updates, and other corporate communications, and use this information alongside news and price data when evaluating UPB.
Upstream Bio, Inc. is calling a virtual 2026 annual stockholder meeting on June 9, 2026 at 9:00 a.m. Eastern Time. Holders of its 54,419,986 outstanding common shares as of April 13, 2026 may vote online on two main items: electing two Class II directors, H. Edward Fleming, Jr., M.D. and Liam Ratcliffe, M.B.Ch.B., Ph.D., M.B.A., to new three‑year terms, and ratifying PricewaterhouseCoopers LLP as independent auditor for the 2026 fiscal year. The company uses “notice and access” to distribute proxy materials electronically, remains an emerging growth and smaller reporting company, and describes its board structure, committee responsibilities, director pay, and executive compensation, including stock‑based incentives and a formal executive severance plan tied to change‑in‑control events.
Upstream Bio, Inc. entered into a Sales Agreement with Leerink Partners LLC to establish an at-the-market equity program. Under a related prospectus supplement, the company may offer and sell shares of its common stock in an aggregate amount of up to $150,000,000 through or to the agent.
Leerink Partners will use commercially reasonable efforts to place shares on Nasdaq or other trading markets and will receive a commission of up to 3.0% of gross proceeds from each sale. Neither party is obligated to sell a minimum amount, and the company or the agent may suspend or terminate the program at any time, subject to the agreement’s terms.
The shares will be issued under Upstream Bio’s automatic shelf registration statement on Form S-3ASR and the prospectus supplement filed on March 26, 2026. Legal opinions from Goodwin Procter LLP regarding the validity of the shares are included as exhibits.
Upstream Bio, Inc. has entered into a sales agreement with Leerink Partners LLC to offer and sell, from time to time, shares of its common stock in an at-the-market offering of up to $150,000,000. The sales agent may sell shares on Nasdaq consistent with market conditions and will receive compensation up to 3.0% of gross proceeds. An illustrative offering at the March 24, 2026 last reported sale price of $8.45 per share would equal $150.0 million or approximately 17,751,479 shares; shares outstanding were 54,237,750 as of December 31, 2025. The prospectus supplement highlights that proceeds treatment, timing and quantities will vary with market conditions, and that the sales agent will be deemed an underwriter for purposes of the Securities Act.
Upstream Bio, Inc. is a clinical-stage biotechnology company focused on inflammatory diseases, initially severe respiratory disorders. Its lead and only product candidate, verekitug, is a fully human monoclonal antibody that blocks the receptor for thymic stromal lymphopoietin (TSLP), a key upstream driver of inflammation.
Verekitug has shown high TSLP receptor occupancy, a favorable safety profile and strong, sustained reductions in asthma biomarkers (eosinophils and FeNO) for up to 24 weeks after dosing in early trials, supporting extended dosing intervals. The company has completed Phase 2 studies in severe asthma and chronic rhinosinusitis with nasal polyps with positive top-line results, and has initiated a Phase 2 trial in COPD and a long-term asthma extension study.
Upstream Bio plans to start Phase 3 trials in severe asthma and CRSwNP in the first quarter of 2027, aiming for high efficacy without biomarker restrictions and quarterly at-home administration. Management sees broader potential for verekitug across multiple TSLP-driven diseases beyond its initial respiratory indications.
Upstream Bio, Inc. reported a larger net loss but strong clinical progress as it prepares for late-stage trials. For the quarter ended December 31, 2025, collaboration revenue was $668,000 and net loss was $42.5 million, compared with a net loss of $21.2 million a year earlier, mainly from higher research spending on verekitug.
Research and development expenses rose to $40.2 million from $21.8 million, while general and administrative expenses increased to $6.7 million from $5.2 million. The company ended 2025 with cash, cash equivalents and short-term investments of $341.5 million, which it expects will fund planned operations through 2027.
The company highlighted positive Phase 2 VALIANT data in severe asthma, with statistically significant reductions in asthma exacerbations at multiple dosing regimens, and supportive analyses from the Phase 2 VIBRANT study in chronic rhinosinusitis with nasal polyps. Upstream Bio plans to advance verekitug into Phase 3 trials in severe asthma and CRSwNP, aiming to start dosing in the first quarter of 2027, and continues enrollment in the Phase 2 VENTURE trial in COPD.
Upstream Bio, Inc. CFO and COO Michael Gray reported an automatic sale of common stock primarily to cover taxes on vested restricted stock units. The transaction involved 852 shares of common stock sold at $9.29 per share. After this sell-to-cover transaction, he directly holds 29,648 common shares. The company has a sell-to-cover policy, and the sale was carried out automatically, not at his discretion.
Upstream Bio, Inc. reported that Chief Medical Officer Aaron Deykin executed an open-market sale of 894 shares of common stock at $9.29 per share on March 16, 2026. According to the company’s sell-to-cover policy, these shares were sold automatically to satisfy tax withholding obligations from vesting restricted stock units and were not sold at his discretion.
Following this tax-related sale, Deykin directly holds 32,687 shares of Upstream Bio common stock.
Upstream Bio, Inc. Chief Executive Officer Everett Rand Sutherland reported an automatic sale of 2,093 shares of common stock at an average price of $9.29 per share. According to the company’s sell-to-cover policy, these shares were sold solely to satisfy tax withholding obligations from vesting restricted stock units.
After this tax-related transaction, Sutherland directly holds 72,907 shares of Upstream Bio common stock. Because the sale was automatic and not at his discretion, it reflects routine tax management rather than a discretionary change in investment stance.
Upstream Bio, Inc. General Counsel Allison Ambrose reported an automatic sale of 475 shares of common stock at $9.29 per share. The company has a “sell-to-cover” policy, so these shares were sold solely to cover tax withholding on vested restricted stock units, not at her discretion. After this transaction, she directly holds 16,525 shares, indicating this was a small, tax-related adjustment to her position rather than a discretionary open-market trade.