Every 8-K that Sutro Biopharma, Inc. (STRO) has filed with the SEC in the last 24 months is listed below, newest first, and each one links through to the document itself with the summary and the scores our analysis gives it.
A 8-K covers material events a company has to report between its quarterly reports, so if you follow STRO and want that one kind of document rather than the whole filing history, this is the page to keep. The company's other filings, of every form, are on the full STRO filings page.
Sutro Biopharma reported second quarter 2026 results and detailed progress across its antibody-drug conjugate pipeline. Revenue for the quarter ended June 30, 2026 was $9.8 million, primarily from its Astellas collaboration, down from $63.7 million a year earlier. Total R&D and G&A expenses declined to $39.5 million from $48.7 million, but net loss widened to $38.5 million versus $11.5 million, or $2.33 loss per share compared with $1.35.
Cash, cash equivalents and marketable securities were $164.3 million as of June 30, 2026, versus $202.6 million as of March 31, 2026, and are expected to support operations into at least the second quarter of 2028. Total assets were $194.5 million and total liabilities $297.8 million, including a $239.1 million deferred royalty obligation, resulting in stockholders’ deficit of $103.3 million.
Clinically, the company highlighted STRO-004 Phase 1 data showing multiple confirmed and ongoing unconfirmed partial responses across several tumor types, mostly low-grade adverse events, a 6% discontinuation rate due to adverse events, and dose-proportional pharmacokinetics with a roughly seven-day half-life. Sutro plans to initiate a Phase 1 trial for STRO-006 in the third quarter of 2026 and submit an IND for dual-payload ADC STRO-227 in 2026, while its first Astellas immunostimulatory ADC program has entered the clinic, triggering a $10 million milestone payment.
Sutro Biopharma, Inc. reported the results of its 2026 Annual Meeting of Stockholders held on June 5, 2026. Stockholders elected directors Jane Chung, Connie Matsui, and James Panek, each receiving more votes “for” than “withheld,” with broker non-votes also recorded.
Stockholders also approved two additional proposals, with one receiving 13,893,289 shares voted for, 501 against, and 5,883 abstaining, and another receiving 11,329,946 shares for, 22,412 against, 6,452 abstentions, and 2,540,863 broker non-votes.
Sutro Biopharma reported first quarter 2026 results showing lower revenue but a much smaller loss as it refocuses its pipeline. Revenue was $14.5 million for the quarter ended March 31, 2026, compared with $17.4 million a year earlier, mainly from its Astellas collaboration.
Net loss narrowed to $38.5 million from $76.0 million as total research, development and general and administrative expenses fell to $44.1 million from $64.9 million, reflecting prior restructuring. Cash, cash equivalents and marketable securities were $202.6 million as of March 31, 2026, up from $141.4 million at year-end 2025, and were further strengthened by a $110.0 million underwritten equity offering, extending cash runway into at least the second quarter of 2028.
Clinically, Sutro advanced its wholly owned ADC programs, including Phase 1 dose escalation of Tissue Factor–targeting STRO-004 with initial safety, pharmacokinetic and early activity data expected in mid-2026, and IND submissions planned in 2026 for ITGB6-targeting STRO-006 and dual‑payload PTK7 program STRO-227. Under its Astellas collaboration, a TROP2-targeted dual-payload iADC entered the clinic, triggering a $10 million milestone payment, while the company closed its luvelta program and stopped additional investment.
Sutro Biopharma, Inc. filed an 8-K announcing termination of its Open Market Sale Agreement with Jefferies, ending its at-the-market equity program, and reporting full-year 2025 results. After the termination, no additional common shares may be sold under that agreement.
For 2025, revenue grew to $102.5 million from $62.0 million in 2024, mainly from Astellas and Ipsen collaborations. Total operating expenses fell to $260.9 million from $300.5 million, even including $53.4 million of restructuring and related costs.
The company reported a net loss of $191.1 million, improved from a $227.5 million loss in 2024, with basic and diluted net loss per share of $22.49. Cash, cash equivalents and marketable securities were $141.4 million as of December 31, 2025, and a recent $110.0 million equity financing extended its cash runway into at least the second quarter of 2028. Sutro highlighted progress across its ADC pipeline, including STRO-004 Phase 1 dosing, planned 2026 INDs for STRO-006 and STRO-227, and Astellas-partnered dual-payload programs generating $17.5 million in milestones.
Sutro Biopharma, Inc. entered an underwriting agreement on February 9, 2026 to sell 7,868,383 shares of common stock at $13.98 per share in an underwritten public offering under its existing shelf registration. The company estimates gross proceeds of about $110.0 million, which, combined with its cash, cash equivalents and marketable securities as of January 1, 2026, is expected to bring total capital resources to approximately $251.4 million.
Sutro plans to use the net proceeds primarily for general corporate purposes, including research, clinical and process development and manufacturing of product candidates, working capital, potential acquisitions or investments, capital expenditures and other corporate needs. Based on its planned use of funds, Sutro estimates this capital will fund operating and capital needs into the second quarter of 2028. The offering is expected to close on February 11, 2026, subject to customary conditions. Sutro is also releasing an updated corporate presentation, which will be available on its website and furnished as an exhibit.
Sutro Biopharma, Inc. reported that it has regained compliance with Nasdaq’s minimum bid price requirement for continued listing on The Nasdaq Global Market. Nasdaq’s Listing Qualifications staff confirmed that, as of December 16, 2025, the closing bid price of Sutro’s common stock had been at least $1.00 per share for 10 consecutive business days and that the company satisfies all other applicable listing criteria. This means the prior listing deficiency has been resolved and the related matter is now closed.
The company had previously been notified on June 20, 2025 that its stock had traded below $1.00 per share for 30 consecutive business days, putting it out of compliance with Nasdaq Listing Rule 5450(a)(1). The new notice confirms that Sutro has successfully corrected this issue and remains listed on The Nasdaq Global Market.
Sutro Biopharma (STRO) furnished an 8-K announcing it issued a press release with financial results for the quarter ended September 30, 2025. The press release is provided as Exhibit 99.1. The company states the information under Item 2.02, including Exhibit 99.1, is being furnished and not filed under the Exchange Act, and is not subject to Section 18 liabilities nor incorporated by reference except as expressly stated.
Sutro Biopharma, Inc. reported a new organizational restructuring to focus on three preclinical antibody-drug conjugate (ADC) programs and its research and development collaborations. The company expects this restructuring, together with anticipated near-term milestone payments, to extend its cash runway into at least mid-2027. As part of the plan, Sutro intends to reduce its workforce by approximately one-third. The company estimates total cash payments and costs related to the program prioritization and workforce reduction will be approximately $4.1 million to $4.3 million, with a significant majority expected to be paid in the fourth quarter of 2025. Following prioritization of its ADC programs, Sutro expects initial clinical data from STRO-004, its next-generation Tissue Factor-targeting exatecan ADC, to be available in 2026.