Sutro Biopharma Presents Promising Preclinical Data Across Its Pipeline of Next-Generation Single and Dual-Payload Adc Programs

Published: 2026-04-20 06:50:53 ET STRO

Published on 04/20/2026 at 06:50 am EDT

Sutro Biopharma, Inc. announced promising preclinical data across its pipeline of next-generation ADCs in five posters and one oral presentation at the American Association for Cancer Research Annual Meeting 2026. Results from a preclinical study of STRO-004, its DAR8 Topo1 ADC targeting Tissue Factor (TF), were reviewed in an oral presentation titled ?STRO-004, an exatecan-based next-generation tissue factor (TF)-targeted ADC, demonstrates superior efficacy across TF-expressing solid tumors in a comprehensive single-mouse PDX trial.? In the preclinical study, STRO-004 demonstrated robust and consistent antitumor activity across a broad range of TF-expressing solid tumor patient-derived xenograft (PDX) models, with improved efficacy compared to benchmark ADCs.

At a single, clinically relevant dose of 5 mg/kg, STRO-004 achieved remarkable disease control and tumor reduction across multiple tumor types. STRO-004?s favorable tolerability, with a highest non-severely toxic dose (HNSTD) of 50 mg/kg, and pharmacokinetic profile are expected to enable increased drug exposure and payload delivery. Exploratory biomarker analyses provide preliminary insight into STRO-004's mechanism of action, suggesting potential for combination studies addressing specific indications in either early or late lines of treatment.

Sutro will present multiple posters highlighting advances across its ADC pipeline and discovery platforms. Preclinical data for STRO-006, an integrin ß6-targeting ADC (DAR 8 exatecan), demonstrated robust, dose-dependent antitumor activity across multiple solid tumor models at a single, clinically relevant dose of 5 mg/kg, including non-small cell lung cancer (NSCLC) and head and neck cancers. The program also shows a favorable pharmacokinetic and tolerability profile, supporting its potential as a differentiated next-generation ADC with IND submission planned for 2026. Preclinical data for STRO-227, a PTK7-targeting dual-payload ADC (DAR 10; 8 exatecan + 2 MMAE), demonstrated robust, dose-dependent antitumor activity across multiple solid tumor models, including breast, ovarian and NSCLC, with improved efficacy versus single-payload ADCs.

The program also shows favorable pharmacokinetics, stable payload delivery, and tolerability comparable to benchmark ADCs, supporting the potential of its dual-payload design. Sutro expects to file an IND for STRO-227, its first wholly-owned dual-payload ADC, in late 2026. Poster: ?Phase 1 open-label study to evaluate safety, pharmacokinetics, and preliminary anti-tumor activity of STRO-004 in adults with refractory/recurrent metastatic solid tumors?

Session Date and Time: April 20, 2026; 9:00 AM-12:00 PM PT. Poster: ?STRO-006: An Integrin beta-6?targeting ADC demonstrates favorable safety profile and potent antitumor activity in preclinical solid tumors? Session Date and Time: April 20, 2026; 9:00 AM-12:00 PM PT.

Poster: ?Preclinical characterization of STRO-227: A PTK7-targeting dual-payload ADC with topoisomerase 1 and tubulin inhibitors? Session Date and Time: April 20, 2026; 9:00 AM-12:00 PM PT. Poster: ?The HER2-targeting dual-payload antibody-drug conjugate combining a topoisomerase I inhibitor and a microtubule inhibitor demonstrates superior efficacy and overcomes resistance to single-payload ADCs in xenograft models?

Session Date and Time: April 20, 2026; 9:00 AM-12:00 PM PT. Poster: ?Sutro?s Site-Specific Dual-Payload ADCs Combining TOPO1i and DNA Damage Response Inhibitors to Enhance Efficacy, Overcome Resistance, and Improve Safety? Session Date and Time: Tuesday, April 21, 2026; 9:00 AM-12:00 PM PT.

Astellas Pharma reviewed preclinical results from its TROP2-targeted iADC program at AACR. The oral presentation, titled ?ASP2998, a TROP2-targeted immunostimulatory antibody-drug conjugate (iADC) with dual payloads, demonstrates potent efficacy and a favorable safety profile in nonclinical models,? highlighted the company?s progress in the development of next-generation iADCs leveraging Sutro?s cell-free protein synthesis platform.

ASP2998 is a first-in-class iADC that combines cytotoxic and immune-stimulatory mechanisms to enhance antitumor efficacy. Inclusion of a STING agonist augments the antitumor efficacy, immune activation and durable tumor immunity of ASP2998, supporting its superior activity over toxin-only anti-TROP2 ADCs. Preclinically, ASP2998 demonstrated a favorable safety profile, supporting a promising therapeutic index.

ASP2998 entered the clinic earlier this year and is actively dosing patients.