Sutro Biopharma to Highlight its Next-Generation Exatecan and Dual-Payload ADC Programs in Presentations at AACR 2025

Rhea-AI Summary

Sutro Biopharma announced two key presentations at the 2025 AACR Annual Meeting in Chicago, showcasing their advances in antibody drug conjugates (ADCs). The company will present data on two significant developments:

• STRO-004: A novel exatecan Tissue Factor ADC showing strong anti-tumor activity and favorable safety in preclinical studies. Single-dose treatments demonstrated promising response rates in Tissue Factor-positive patient models across multiple cancers. The company plans to begin human trials later this year.
• XpressCF+® Platform: Their proprietary cell-free platform enables creation of dual-payload ADCs with higher drug-to-antibody ratios and site-selective conjugation of two linker payloads.

CEO Jane Chung highlighted that STRO-004 achieved notable disease control rates in preclinical studies. The presentations will take place on April 28, with Dr. Alice Yam presenting on STRO-004 and Dr. Gang Yin discussing dual-payload ADC development. The research demonstrates Sutro's leadership in developing next-generation cancer treatments.

Positive

• STRO-004 demonstrated potent anti-tumor activity in preclinical studies across all tested doses
• Single dose of STRO-004 achieved promising response rates in Tissue Factor-positive patient-derived xenograft models
• Company's XpressCF+® platform enables creation of advanced dual-payload ADCs with higher drug-to-antibody ratios
• IND-enabling studies progressing with first-in-human trial planned for later this year
• Platform demonstrates validated cell-free ADC manufacturing process

Negative

• STRO-004 data is only preclinical - no human trial results yet
• Success in preclinical studies does not guarantee effectiveness in human trials

- Preclinical findings show STRO-004's promising anti-tumor activity and favorable safety profile -

SOUTH SAN FRANCISCO, Calif., April 28, 2025 (GLOBE NEWSWIRE) -- Sutro Biopharma, Inc. (Sutro or the Company) (NASDAQ: STRO), an oncology company pioneering site-specific and novel-format antibody drug conjugates (ADCs), today announced poster presentations at the upcoming 2025 American Association for Cancer Research (AACR) Annual Meeting, taking place April 25-30 in Chicago, IL. The presentations will cover preclinical activity and safety data for STRO-004, the Company’s novel exatecan Tissue Factor ADC, as well as showcase the unique advantages of Sutro’s XpressCF+^® platform in enabling precise and efficient development of dual-payload ADCs.

“We are excited to share our progress advancing our next-generation ADC pipeline at AACR,” said Jane Chung, Sutro’s Chief Executive Officer. “In preclinical studies, STRO-004 consistently demonstrated potent, dose-dependent anti-tumor activity and a favorable safety profile across all tested doses. Of note, STRO-004, after only a single dose, achieved promising overall response and disease control rates in Tissue Factor-positive patient-derived xenograft models spanning multiple cancer types. We look forward to continuing to investigate the full potential of STRO-004, as we complete IND-enabling studies and prepare to initiate a first-in-human trial later this year.”

Ms. Chung continued: “Also, as presented at AACR, our XpressCF+^® cell-free platform is uniquely capable of creating revolutionary dual-payload ADCs—differentiated by higher drug-to-antibody ratios, fully site-selective conjugation of two linker payloads and a validated, cell-free ADC manufacturing process. We are excited to showcase these and other key features of our platform, which enable our ADC candidates to overcome limitations of conventional ADCs and the challenges of targeting complex disease biology. These presentations further reinforce our technology leadership and our highly differentiated ADC candidates.”

Poster Presentation Details:

Title: Preclinical activity and safety of STRO-004, a novel ADC targeting tissue factor for solid tumors
Abstract: #1572
Session: PO.ET02.01 - Antibody-Based Cancer Therapeutics 1
Date & Time: Monday, April 28, 2025, 9:00 a.m. - 12:00 p.m. CT
Presenter: Alice Yam, Ph.D., Vice President of Drug Discovery at Sutro Biopharma

Title: Enhancing Topo1i ADC efficacy: development of homogeneous dual-payload ADCs combining Topo1i with microtubule inhibitors or PARP inhibitors
Abstract: #2870
Session: PO.ET02.11 - Antibody-Based Cancer Therapeutics 2
Date & Time: Monday, April 28, 2025, 2:00 p.m. - 5:00 p.m. CT
Presenter: Gang Yin, Ph.D., Vice President of Platform Engineering & Process Research at Sutro Biopharma

The abstracts are currently available on AACR’s website and the poster presentations will be accessible through the News & Events page of the Investor Relations section of the Company’s website at www.sutrobio.com.

About Sutro Biopharma
Sutro Biopharma, Inc., is relentlessly focused on the discovery and development of precisely designed cancer therapeutics to transform what science can do for patients. Sutro’s fit-for-purpose technology, including cell-free XpressCF^®, provides the opportunity for broader patient benefit and an improved patient experience. Sutro is advancing a robust early-stage pipeline of novel exatecan and dual-payload antibody drug conjugates (ADCs), coupled with high-value collaborations and industry partnerships, which validate its continuous product innovation. Sutro is headquartered in South San Francisco. 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, including enrollment and site activation; timing of announcements of clinical results, trial initiation, and regulatory filings; outcome of discussions with regulatory authorities; potential benefits of the Company’s product candidates and platform; potential business development and partnering transactions; potential market opportunities for the Company’s product candidates; the timing and receipt of anticipated future milestone payments; the Company’s expected cash runway; and the expected costs and cost reductions associated with the restructuring. 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 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, and the Company’s commercial collaborations with third parties 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

FAQ

What are the key findings of STRO-004 presented at AACR 2025?

STRO-004, Sutro's Tissue Factor ADC, demonstrated potent anti-tumor activity and favorable safety across all tested doses in preclinical studies. After a single dose, it achieved promising response rates in Tissue Factor-positive patient-derived xenograft models across multiple cancer types.

When will Sutro Biopharma (STRO) begin human trials for STRO-004?

Sutro Biopharma plans to initiate first-in-human trials for STRO-004 later in 2025, following completion of their current IND-enabling studies.

What makes Sutro's XpressCF+ platform unique for ADC development?

Sutro's XpressCF+ platform uniquely creates dual-payload ADCs with higher drug-to-antibody ratios, fully site-selective conjugation of two linker payloads, and uses a validated cell-free ADC manufacturing process.

What presentations will Sutro Biopharma (STRO) give at AACR 2025?

Sutro will present two posters at AACR 2025: one on STRO-004's preclinical activity and safety on April 28 at 9:00 AM CT, and another on dual-payload ADCs combining Topo1i with other inhibitors at 2:00 PM CT.

How does STRO-004 differ from conventional ADCs?

STRO-004 is designed to overcome limitations of conventional ADCs through Sutro's XpressCF+ platform, specifically targeting Tissue Factor with improved drug-to-antibody ratios and site-selective conjugation for better efficacy.