Sutro Biopharma, Inc. (STRO) came out with a quarterly loss of $0.14 per share versus the Zacks Consensus Estimate of a loss of $0.39. This compares to a loss of $0.59 per share a year ago. These figures are adjusted for non-recurring items.This quarterly report represents an earnings surprise of +64.10%. A quarter ago, it was expected that this company would post a loss of $0.63 per share when it actually produced a loss of $0.91, delivering a surprise of -44.44%.Over the last four quarters, the company ha ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ________ to ________ Commission File Number: 001-38662 SUTRO BIOPHARMA, INC. (Exact Name of Registrant as Specified in its Charter) Delaware 47-0926186 (State ...

Exhibit 99.1 Sutro Biopharma Reports Second Quarter 2025 Financial Results and Business Highlights – On track to initiate FIH study with STRO-004, potential best-in-class Tissue Factor ADC, in the second half of 2025 – – Expanded breadth of preclinical data across pipeline, including STRO-006 and dual-payload ADCs – – Entered research collaboration with the FDA to advance regulatory standards for ADCs – – Industry veteran Greg Chow appointed as Chief Financial Officer – – Cash, cash equivalents and marketab ...

– On track to initiate FIH study with STRO-004, potential best-in-class Tissue Factor ADC, in the second half of 2025 – – Expanded breadth of preclinical data across pipeline, including STRO-006 and dual-payload ADCs – – Entered research collaboration with the FDA to advance regulatory standards for ADCs – – Industry veteran Greg Chow appointed as Chief Financial Officer – – Cash, cash equivalents and marketable securities as of June 30, 2025 of $205.1 million, with cash runway into early 2027 – SOUTH SAN ...

Sutro Biopharma (STRO) Conference Call Summary Company Overview - **Company**: Sutro Biopharma (STRO) - **Industry**: Biotechnology, specifically focusing on Antibody-Drug Conjugates (ADCs) Key Points and Arguments Strategic Reprioritization - Sutro Biopharma is undergoing a strategic reprioritization to maximize the value of its unique ADC platform, emphasizing the optimization of all components from antibody to linker to payload [3][5][9] Technology and Product Differentiation - The company has made significant improvements in product design and manufacturing, particularly with a proprietary beta glucuronidase linker that cleaves more in tumors and less outside, reducing toxicities like neutropenia [6][9] - Sutro's platform allows for the combination of multiple payloads, enhancing the ability to target complex biological systems, which is referred to as "protein engineering on steroids" [7][8][9] Pipeline and Clinical Programs - Sutro plans to deliver three Investigational New Drug (IND) applications over the next three years, with a focus on: 1. Tissue Factor Program (DAR8 exatecan) 2. Integrin Beta-Six Program (DAR8 exatecan) 3. Dual Payload ADCs [12][14] - The Tissue Factor program is highlighted as the lead, showing a 50-fold increase in exposure compared to existing approved agents, with a high non-severe toxic dose (HNSTD) of 50 mg/kg [16][18] Safety and Efficacy - Sutro's ADCs are designed to avoid engaging Fc gamma receptors, which helps in reducing ocular toxicities associated with other ADCs [21][22] - The company aims to demonstrate clinical differentiation through higher dosing and improved safety profiles compared to existing therapies [18][41] Competitive Landscape - Sutro is positioning itself against competitors by focusing on the safety and efficacy of its ADCs, particularly in lung cancer, where it aims to avoid introducing lung toxicity [42][43] - The company is also exploring the potential of dual payload ADCs to overcome resistance seen in single payload therapies, which is a growing area of interest in the industry [50][55] Partnerships and Financial Outlook - Sutro has strategic collaborations with Ipsen and Astellas, which could provide up to $2 billion in potential milestones and royalties [71] - As of Q1, Sutro reported cash reserves of approximately $250 million, extending its runway into early 2027, not including anticipated milestones from collaborations [72] Future Directions - Sutro is committed to advancing its dual payload ADCs, with an IND expected in 2027, and is actively working on preclinical models to establish the safety and efficacy of these new therapies [61][64] Additional Important Information - The decision to deprioritize the Ryvelta program was based on strategic considerations rather than safety or data issues, indicating a shift towards next-generation products [67][68] - The company is focused on addressing unmet needs in oncology, particularly for patients unresponsive to current immunotherapies [60] This summary encapsulates the key insights from the conference call, highlighting Sutro Biopharma's strategic direction, technological advancements, clinical pipeline, competitive positioning, and financial outlook.

Company Overview - Sutro Biopharma, Inc. is focused on the discovery and development of precisely designed cancer therapeutics, particularly antibody drug conjugates (ADCs) [7] - The company is advancing a robust early-stage pipeline of novel exatecan-based and dual-payload ADCs, supported by high-value collaborations and industry partnerships [7] Leadership Appointment - Greg Chow has been appointed as Chief Financial Officer (CFO) effective June 2, 2025, bringing over 25 years of executive leadership experience in corporate finance, capital markets, and drug development operations [1][2] - Chow's previous roles include Chief Financial and Business Officer at NodThera, CFO at Freenome Holdings, and CFO at Frontier Medicines, where he successfully executed significant financing rounds [2][3] Financial Strategy and Goals - The leadership of Greg Chow is expected to enhance financial discipline, operational efficiency, and capital strategy, positioning the company to achieve key clinical milestones [2] - Chow expressed enthusiasm about joining Sutro, highlighting the company's unique position in ADC innovation and its powerful cell-free technology platform for drug discovery [2] Inducement Grants - Sutro has granted Greg Chow a restricted stock unit award for 100,000 shares and a non-qualified option to purchase 275,000 shares under the 2021 Equity Inducement Plan [4][5] - The option will have an exercise price equal to the closing price of Sutro's common stock on the appointment date, with vesting schedules for both the restricted stock and option awards [6]

Sutro Biopharma (STRO) FY Conference Summary Company Overview - **Company**: Sutro Biopharma - **Event**: TD Cowen's Sixth Annual Oncology Innovation Summit - **Date**: May 28, 2025 Key Points Strategic Changes - Sutro Biopharma conducted a strategic review to enhance shareholder value, leading to a focus on advancing their second and third generation Antibody-Drug Conjugates (ADCs) pipeline [3][4] - The development of Lavelta has been deprioritized, but insights gained will inform future product design and clinical strategies [4][5] ADC Pipeline Differentiation - Sutro claims to have one of the most powerful ADC technologies, optimizing every component from antibody to linker to payload [8] - The next generation ADCs are designed to target complex biological targets, utilizing both single and dual payloads [8][9] - Dual payload ADCs are expected to overcome resistance seen in single payload ADCs, providing targeted chemotherapy and combination therapy [9][10] Safety and Efficacy - Sutro's platform allows for higher dosing compared to competitors, with a therapeutic index that can be optimized for safety [10][12] - The company has seen significant preclinical data indicating a two to threefold higher pharmacokinetics (PK) compared to competitors, which may translate into better patient outcomes [24][25] - The manufacturing process in cell-free extracts avoids glycosylation, reducing potential toxicity [17][20] STRO-four Development - STRO-four is a tissue factor ADC with a DAR-eight exotecan and proprietary beta glue linker, designed to minimize on-target liabilities [39][40] - Sutro aims to file an Investigational New Drug (IND) application in the second half of 2025, with first-in-human studies expected by year-end [47] - The ADC is anticipated to have 50-fold higher exposure compared to the approved competitor, Tisotumab vedotin, which could lead to improved patient benefits [49][50] Future Programs - STRO-six, another ADC program, targets integrin beta-six and is expected to have a significant commercial opportunity, particularly in lung cancer [53] - The platform's ability to avoid interstitial lung disease (ILD) is highlighted as a critical factor for success in lung cancer treatments [55] Additional Insights - Sutro's approach to selecting payloads and linkers is data-driven, focusing on combinations that enhance therapeutic index while minimizing safety risks [35][36] - The company is exploring the potential for three payload combinations to further enhance treatment efficacy against resistant tumors [34] Conclusion - Sutro Biopharma is positioning itself as a leader in the ADC space with innovative technologies and a focus on safety and efficacy, aiming to address unmet needs in oncology treatments. The upcoming IND filings and clinical trials are critical milestones for the company.

Sutro Biopharma (STRO) 2025 Conference Summary Company Overview - Sutro Biopharma is focused on advancing its next-generation antibody-drug conjugates (ADCs) technology, aiming to differentiate from conventional ADCs and enhance commercial viability [3][4][5] Key Points and Arguments 1. **Strategic Reprioritization**: The company has deprioritized its late-stage program for loveltomab tazavibulin, focusing instead on a new pipeline strategy that emphasizes innovative ADCs [3][4] 2. **Next-Generation ADCs**: Sutro is developing ADCs targeting hard-to-reach targets, which are more complex and widely expressed across solid tumors, ensuring better commercial viability [4][5] 3. **Clinical Development Plans**: Sutro aims to deliver three Investigational New Drug (IND) applications over the next three years, starting with STRO-four in the second half of 2025, followed by STRO-six in 2026 and a dual payload ADC in 2027 [4][6] 4. **Innovative Technology**: The company claims to have one of the most powerful ADC technologies, optimizing every component of the ADC to achieve a wider therapeutic index [3][9] 5. **Dual Payload ADCs**: Sutro is focusing on dual payload ADCs, which have the potential to overcome resistance seen in single payload ADCs, providing a competitive edge in the market [6][24][25] 6. **Clinical Efficacy**: Preliminary data suggests that STRO-four has significantly higher exposure and antitumor activity compared to conventional ADCs, with a 17-fold increase in Cmax and a 50-fold increase in exposure at HNSCD [14][20] 7. **Target Selection**: The company emphasizes the importance of selecting patients based on target antigen expression, which enhances the likelihood of positive clinical outcomes [21] Additional Important Content 1. **Collaboration and Partnerships**: Sutro is collaborating with Astellas on dual payload ADCs, which is advancing rapidly and is seen as a significant opportunity for the company [26][29] 2. **Manufacturing Capabilities**: Sutro has developed a robust external CDMO network to improve cost efficiency and speed in ADC manufacturing, which supports its early pipeline [4][7] 3. **Competitive Landscape**: The ADC market is becoming congested, particularly with common targets like FR alpha, which may affect commercial viability; Sutro's focus on unique targets aims to mitigate this risk [5][6] 4. **Regulatory Simplicity**: The development of dual payload ADCs is seen as advantageous due to regulatory simplicity compared to combining multiple compounds [25][30] 5. **Pipeline Execution**: Sutro's leadership team, with extensive ADC oncology experience, is focused on executing the innovative pipeline and achieving key deliverables [31][32]

Company Performance - Sutro Biopharma, Inc. reported a quarterly loss of $0.91 per share, which was worse than the Zacks Consensus Estimate of a loss of $0.63, representing an earnings surprise of -44.44% [1] - The company posted revenues of $17.4 million for the quarter ended March 2025, exceeding the Zacks Consensus Estimate by 25.83%, compared to revenues of $13.01 million in the same quarter last year [2] - Over the last four quarters, Sutro Biopharma has surpassed consensus EPS estimates two times and topped consensus revenue estimates two times [2] Stock Performance - Sutro Biopharma shares have declined approximately 46% since the beginning of the year, contrasting with the S&P 500's decline of -4.3% [3] - The company's current consensus EPS estimate for the upcoming quarter is -$0.53 on revenues of $13.6 million, and for the current fiscal year, it is -$2.06 on revenues of $53.34 million [7] Industry Outlook - The Medical - Biomedical and Genetics industry, to which Sutro Biopharma belongs, is currently in the top 33% of over 250 Zacks industries, indicating a favorable outlook [8] - Empirical research suggests a strong correlation between near-term stock movements and trends in earnings estimate revisions, which can impact Sutro Biopharma's stock performance [5][6]

Core Insights - Sutro Biopharma is shifting its focus from luvelta to its pipeline of novel exatecan and dual-payload ADCs, with STRO-004 being prioritized as the lead clinical candidate due to strong preclinical data indicating its best-in-class potential [2][3][6] - The company aims to deliver three new INDs over the next three years, starting with STRO-004 expected to enter clinical studies in the second half of 2025 [2][6][7] - Sutro's financial results for Q1 2025 show revenue of $17.4 million, an increase from $13.0 million in Q1 2024, primarily driven by the Astellas collaboration [13][19] - As of March 31, 2025, Sutro had cash, cash equivalents, and marketable securities totaling $249.0 million, down from $316.9 million at the end of 2024, with a cash runway expected into early 2027 [12][21] Corporate and Program Updates - The company completed a strategic portfolio review in March, leading to the prioritization of wholly-owned next-generation ADC programs while deprioritizing the development of luvelta [3][6] - Sutro is currently conducting an IND-enabling toxicology study for a dual-payload ADC program in collaboration with Astellas, which has triggered a $7.5 million milestone payment [6][8] - The restructuring plan includes a nearly 50% reduction in organizational headcount and the decommissioning of its manufacturing facility by the end of 2025 [11] Pipeline Developments - STRO-004, a next-generation Tissue Factor-targeting ADC, is set to enter clinical studies in the second half of 2025, focusing on solid tumors [7] - STRO-006, an integrin beta-6 ADC, is expected to enter clinical development in 2026 [7] - Sutro anticipates filing an IND for its first wholly-owned dual-payload ADC in 2027 [7] Financial Highlights - Total operating expenses for Q1 2025 were $85.9 million, compared to $69.6 million in Q1 2024, with R&D expenses at $51.6 million and G&A expenses at $13.3 million [14][20] - The net loss for Q1 2025 was $75.97 million, compared to a net loss of $58.21 million in Q1 2024, with a net loss per share of $0.91 [20][19] - Restructuring costs for Q1 2025 amounted to $21.0 million, with expectations for continued recognition of these costs in future periods [16]