Sutro Biopharma Reports Second Quarter 2026 Financial Results and Provides Early Update on STRO-004 Phase 1 Study
Rhea-AI Summary
Sutro Biopharma (NASDAQ: STRO) reported second quarter 2026 revenue of $9.8 million, down from $63.7 million a year earlier, and a net loss of $38.5 million ($2.33 per share). Total R&D and G&A expenses declined to $39.5 million from $48.7 million.
Cash, cash equivalents and marketable securities were $164.3 million as of June 30, 2026; the company expects this to fund operations into at least the second quarter of 2028. Sutro highlighted early data from its STRO-004 Phase 1 STRIVE-01 study, with multiple partial responses across three tumor types, a favorable tolerability profile with a 6% AE-related discontinuation rate, and PK consistent with preclinical data. STRO-006 remains on track to start Phase 1 in the third quarter of 2026, STRO-227 is expected to file an IND in 2026, and Astellas’ second dual-payload iADC program is anticipated to enter the clinic in the second half of 2026.
Positive
- STRO-004 Phase 1 early responses across three tumor types with 6% AE-related discontinuation
- R&D and G&A expenses fell to $39.5M from $48.7M YoY in Q2
- Cash, cash equivalents and marketable securities of $164.3M with runway into at least Q2 2028
- $10M milestone payment from Astellas in April 2026 under dual-payload iADC collaboration
- STRO-006 expected to enter Phase 1 in Q3 2026; STRO-227 IND on track for 2026
Negative
- Revenue declined to $9.8M from $63.7M for Q2 2025
- Net loss widened to $38.5M from $11.5M YoY in Q2
- Non-cash interest expense on sale of future royalties was $9.9M in Q2 2026
- Deferred royalty obligation of $239.1M exceeds total assets of $194.5M
- Stockholders’ deficit was $103.3M as of June 30, 2026
News Explained
As of June 30, 2026, cash was lower than in March while liabilities exceeded assets, leaving Sutro with a reported stockholders’ deficit.
Sutro Biopharma reported second-quarter results while its STRO-004 Phase 1 study remains ongoing; dose optimization is continuing between
The release describes the clinical findings as observations from the ongoing study as of
Cash was
The next specified resolution point is a further STRIVE-01 update targeted for the first half of 2027; expansion cohorts are also planned for that period.
Key Figures
Historical Context
| Date | Event | Sentiment | 24h Move | Catalyst |
|---|---|---|---|---|
| May 14 | First-quarter earnings | Positive | +1.4% | Reported quarterly results, pipeline progress, and cash runway extending into at least Q2 2028. |
| Apr 19 | Preclinical data | Positive | +9.6% | Presented antitumor activity across next-generation single- and dual-payload ADC programs. |
| Mar 23 | Full-year earnings | Positive | +10.5% | Reported 2025 financial results, equity proceeds, and advancement of clinical programs. |
| Feb 25 | Investor conferences | Neutral | +4.9% | Announced management participation in multiple upcoming healthcare investor conferences. |
| Feb 23 | ADC conference | Neutral | -0.1% | Announced participation in the World ADC London Summit and planned scientific presentations. |
24h Move is the share-price change in the day after each event; other market factors may also have contributed.
The three prior positive earnings or pipeline announcements were followed by positive 24-hour reactions, while conference notices produced mixed reactions.
Key Terms
pharmacokinetics medical
maximum tolerated dose medical
recist-evaluable medical
dose-limiting toxicities medical
at-the-market financial
AI-generated analysis. How Rhea-AI works. Not financial advice.
– Encouraging early clinical activity including confirmed and ongoing unconfirmed partial responses with favorable tolerability, and pharmacokinetics (PK) observed in ongoing STRO-004 Phase 1 study –
– Strong execution of STRO-004 STRIVE-01 study with rapid enrollment of initial dose escalation cohorts within 7 months; dose optimization ongoing between 4-5 mg/kg –
– STRO-006, next-generation integrin 6 (ITGB6)-targeting ADC, is on track to enter the clinic in the third quarter of 2026 –
– Second dual-payload iADC program from Sutro’s platform under Astellas collaboration expected to enter the clinic in the second half of 2026 –
– Strong balance sheet with
SOUTH SAN FRANCISCO, Calif., Aug. 12, 2026 (GLOBE NEWSWIRE) -- Sutro Biopharma, Inc. (Sutro or the Company) (NASDAQ: STRO), a clinical-stage oncology company pioneering site-specific and novel-format antibody drug conjugates (ADCs), today reported its financial results for the second quarter ended June 30, 2026 and recent business highlights. Sutro also provided data showing a favorable tolerability profile and early signals of clinical activity from its ongoing Phase 1 study of STRO-004, the Company’s potential best-in-class Tissue Factor (TF)-targeting DAR8 exatecan ADC, in heavily pretreated patients with advanced solid tumors.
“During the second quarter, we continued to execute swiftly across our next-generation ADC portfolio, highlighted by encouraging early clinical data from our ongoing Phase 1 study of STRO-004, having rapidly enrolled our initial dose escalation cohorts in just seven months and now optimizing our go-forward dose,” said Jane Chung, Sutro’s Chief Executive Officer. “We have observed early clinical responses alongside favorable safety, tolerability, and a differentiated pharmacokinetic (PK) profile in patients with few remaining treatment options. The favorable tolerability profile and wider therapeutic index of our DAR8 exatecan ADC allows us to dose higher than other TF-targeting ADCs. These findings strengthen our confidence in STRO-004’s potential to deliver meaningful clinical benefit and provide the opportunity to safely combine with other therapies, while further validating our proprietary ADC platform.”
“Additionally, we are excited to enter the clinic with STRO-006 in the near future, our second clinical program in less than a year, reflecting the continued acceleration of our pipeline strategy. We also look forward to advancing STRO-227, our first wholly-owned dual-payload ADC, toward IND submission later this year, joining our partner Astellas’ dual-payload iADC programs in the clinic. Our progress this quarter underscores the continued advancement of our portfolio and our commitment to delivering differentiated therapies for patients while creating long-term value for shareholders.”
Wholly-Owned Pipeline
STRO-004 Early Safety and Signals of Clinical Activity Highlights:
Dose escalation continues with strong execution, with dose levels 1–5 mg/kg (n=49) enrolled faster than expected. The study, called STRIVE-01, is currently optimizing between doses of 4 and 5 mg/kg, and the maximum tolerated dose has not yet been defined. This US-only based trial, which began in November 2025, includes heavily pretreated patients (median of 3 prior lines of therapy [range 1–7]) across eight tumor types unselected for TF expression. In pancreatic and colorectal cancer patients,
- Multiple responses, including confirmed and ongoing unconfirmed partial responses, across three tumor types in RECIST-evaluable patients to date; including pancreatic cancer, head and neck cancer, and non-small cell lung cancer at dose levels 3-4 mg/kg
- Favorable tolerability profile, with mostly low-grade adverse events (AEs) observed Overall discontinuation rate due to AEs was low at
6% .- All-grade treatment related adverse events (TRAEs) >
15% were nausea (33% ), fatigue (29% ), and anemia (18% ) - Other TRAEs of note that occurred in >
5% of patients included:- Hematologic events: Neutrophil count decreased (
6% ), platelet count decreased (6% ) - On-target TF-related events: Epistaxis (
12% ), stomatitis (10% ), mucosal inflammation (8% ), conjunctivitis (8% ), dry eye (7% ); these events were predominantly grade 1-2 - Grade 3+ events: Anemia (
14% ); all grade 3
- Hematologic events: Neutrophil count decreased (
- DLTs occurred only at the highest dose level tested (5 mg/kg), and appeared to be largely driven by target-related toxicity, resulting in dose reduction but no study drug discontinuations
- All-grade treatment related adverse events (TRAEs) >
- Predictable PK in patients, consistent with preclinical data, demonstrating dose-proportional ADC exposures at all doses, with no evidence of Target Mediated Drug Disposition
- STRO-004 has a half-life of nearly seven days, preserving
98% DAR8 configuration, while free exatecan concentration remains low, delayed, and formation-limited
- STRO-004 has a half-life of nearly seven days, preserving
“We are encouraged by the emerging STRO-004 clinical PK profile, which demonstrate the stability of our ADC construct and validate the design principles of our platform,” said Hans-Peter Gerber, Ph.D., Sutro’s Chief Scientific Officer. “Compared with conventional DAR8 exatecan ADCs, STRO-004 delivered 25
The next STRIVE-01 study update is targeted for the first half of 2027. Initiation of expansion cohorts is planned for the first half of 2027.
STRO-006: Sutro’s next-generation, highly selective integrin β6 (ITGB6)-targeting ADC with a DAR8 exatecan payload, is designed for the treatment of multiple solid tumors. The Company expects to initiate a Phase 1 clinical trial in the third quarter of 2026.
STRO-227: Sutro’s wholly-owned DAR10 dual-payload ADC targeting PTK7, consisting of MMAE (DAR2) and exatecan (DAR8) payloads to enable complementary mechanisms of action within a single molecule. The program remains on track for IND submission in 2026 and represents a key component of Sutro’s strategy to expand its pipeline of novel-format dual-payload ADCs.
Next-Generation ADC Collaborations
Astellas: Two research and development programs are progressing under Sutro’s collaboration with Astellas focused on dual-payload immunostimulatory ADCs (iADCs).
The first program, which targets TROP2, continues to actively dose patients, resulting in a
The second program continues to progress under the collaboration, and based on current development timelines, Sutro expects Astellas to enter the clinic by the end of 2026.
Investor Conferences
Management will participate in the following upcoming healthcare investor conferences. When available, the webcasts of the presentations will be accessible through the News & Events page of the Investor Relations section of the Company’s website at www.sutrobio.com. Archived replays will be available for at least 30 days after the event.
Wells Fargo 21st Annual Healthcare Conference (Boston, MA • September 8–10)
Cantor Global Healthcare Conference (New York, NY • September 9–11)
H.C. Wainwright 28th Annual Global Investment Conference (New York, NY • September 14–16)
Second Quarter 2026 Financial Highlights
Cash, Cash Equivalents and Marketable Securities
As of June 30, 2026, Sutro had cash, cash equivalents and marketable securities of
Revenue
Revenue was
Research & Development (R&D) and General & Administrative (G&A) Expenses
Total R&D and G&A expenses for the quarter ended June 30, 2026 were
About Sutro Biopharma
Sutro Biopharma, Inc. is a clinical-stage biotechnology company advancing a next-generation antibody-drug conjugate (ADC) platform designed to deliver single- and dual-payload ADCs that enable meaningful breakthroughs for patients with cancer. By fully optimizing the antibody, linker, and payload, Sutro’s cell-free platform produces ADCs that are engineered to improve drug exposure, reduce side effects, and expand the range of treatable tumor types. With unique capabilities in dual-payload ADCs, Sutro aims to overcome treatment resistance and redefine what’s possible in cancer therapy. The Company’s pipeline of single- and dual-payload ADCs targets large oncology markets with limited treatment options and significant need for improved therapies.
For more information, follow Sutro on social media @Sutrobio or visit www.sutrobio.com.
Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995, including, but not limited to, anticipated preclinical and clinical development activities; timing of announcements of IND submissions, trial initiation, clinical results, and other regulatory filings; outcome of discussions with regulatory authorities; potential benefits, efficacy and safety profile of the Company’s product candidates and platform; potential business development and partnering transactions; potential market opportunities for the Company’s product candidates; the positing of the Company’s product candidates in the competitive landscape; the timing and receipt of anticipated future milestone and royalty payments; and the Company’s expected cash runway. All statements other than statements of historical fact are statements that could be deemed forward-looking statements. Although the Company believes that the expectations reflected in such forward-looking statements are reasonable, the Company cannot guarantee future events, results, actions, levels of activity, performance or achievements, and the timing and results of biotechnology development and potential regulatory approval is inherently uncertain. Forward-looking statements are subject to risks and uncertainties that may cause the Company’s actual activities or results to differ significantly from those expressed in any forward-looking statement, including risks and uncertainties related to the Company’s ability to advance its product candidates, the receipt and timing of potential regulatory designations, approvals and commercialization of product candidates, the market size for the Company’s product candidates to be smaller than anticipated, clinical trial sites, supply chain and manufacturing facilities, the Company’s ability to obtain, maintain and recognize the benefits of certain designations received by product candidates, the timing and results of preclinical and clinical trials, the Company’s ability to fund development activities and achieve development goals, the Company’s ability to protect intellectual property, the Company’s commercial collaborations with third parties, the impact of health pandemics, tariffs, regional geopolitical conflicts, changes in interest rates, inflation, potential uncertainty with respect to the debt ceiling and government shutdowns, and other risks and uncertainties described under the heading “Risk Factors” in documents the Company files from time to time with the Securities and Exchange Commission. These forward-looking statements speak only as of the date of this press release, and the Company undertakes no obligation to revise or update any forward-looking statements to reflect events or circumstances after the date hereof.
Investor Contact
Emily White
Sutro Biopharma
(650) 823-7681
ewhite@sutrobio.com
Media Contact
Amy Bonanno
Lyra Strategic Advisory
abonanno@lyraadvisory.com
| Sutro Biopharma, Inc. Selected Statements of Operations Financial Data (Unaudited) (In thousands, except share and per share amounts) | |||||||||
| Three Months Ended | |||||||||
| June 30, | |||||||||
| 2026 | 2025 | ||||||||
| Revenue | $ | 9,839 | $ | 63,745 | |||||
| Operating expenses | |||||||||
| Research and development | 31,695 | 38,325 | |||||||
| General and administrative | 7,831 | 10,343 | |||||||
| Restructuring and related costs | 201 | 18,422 | |||||||
| Total operating expenses | 39,727 | 67,090 | |||||||
| Loss from operations | (29,888 | ) | (3,345 | ) | |||||
| Interest income | 1,723 | 2,519 | |||||||
| Non-cash interest expense related to the sale of future royalties | (9,862 | ) | (9,647 | ) | |||||
| Interest and other income (expense), net | (505 | ) | (1,044 | ) | |||||
| Loss before provision for income taxes | (38,532 | ) | (11,517 | ) | |||||
| Provision for / (benefit) from income taxes | 1 | (18 | ) | ||||||
| Net loss | $ | (38,533 | ) | $ | (11,499 | ) | |||
| Net loss per share, basic and diluted | $ | (2.33 | ) | $ | (1.35 | ) | |||
| Weighted-average shares used in computing basic and diluted loss per share | 16,571,602 | 8,511,985 | |||||||
| Sutro Biopharma, Inc. Selected Balance Sheets Financial Data (Unaudited) (In thousands) | ||||||||
| June 30, | December 31, | |||||||
| 2026(1) | 2025(2) | |||||||
| Assets | ||||||||
| Cash, cash equivalents and marketable securities | $ | 164,346 | $ | 141,428 | ||||
| Accounts receivable | 5,797 | 3,977 | ||||||
| Property and equipment, net | 8,357 | 10,648 | ||||||
| Operating lease right-of-use assets | 8,467 | 10,903 | ||||||
| Other assets | 7,495 | 6,874 | ||||||
| Total Assets | $ | 194,462 | $ | 173,830 | ||||
| Liabilities and Stockholders’ Equity | ||||||||
| Accounts payable, accrued expenses and other liabilities | $ | 41,476 | $ | 58,482 | ||||
| Deferred revenue | 6,456 | 12,590 | ||||||
| Operating lease liability | 10,783 | 15,674 | ||||||
| Deferred royalty obligation related to the sale of future royalties | 239,064 | 219,536 | ||||||
| Total liabilities | 297,779 | 306,282 | ||||||
| Total stockholders’ deficit | (103,317 | ) | (132,452 | ) | ||||
| Total Liabilities and Stockholders’ Deficit | $ | 194,462 | $ | 173,830 | ||||
(1) The condensed balance sheet as of June 30, 2026 was derived from the unaudited financial statements included in the Company's Quarterly Report on Form 10-Q for the quarter ended June 30, 2026, filed with the Securities and Exchange Commission on August 12, 2026.
(2) The condensed balance sheet as of December 31, 2025 was derived from the audited financial statements included in the Company's Annual Report on Form 10-K for the year ended December 31, 2025, filed with the Securities and Exchange Commission on March 23, 2026.
