Reports Q1: '004 Safety/Tolerability Will Be Focus Of Initial Data Mid-Year

Research evidence excerpt

Reports Q1: '004 Safety/Tolerability Will Be Focus Of Initial Data Mid-Year

TD Cowen Sutro Biopharma

Global Research May 14, 2026

AT A GLANCE

Our Investment Thesis Forthcoming Catalysts

Sutro is a clinical stage biotechnology company with a proprietary protein synthesis technology ■ Initial Phase I data for STRO-004 in solid

(XpressCF) that the company is applying to the productions of ADCs, bispecific antibodies, and tumors (Mid-2026)

cytokine-based IO therapeutics. XpressCF platform uses a cell-free protein production process ■ Initiate FIH study for STRO-006 (2026)

to generate homogeneous product from DNA sequences, which can potentially shorten the time ■ Dual-payload ADC IND filing (2026)

to take a candidate to the IND stage by 9-15 months. While the company deprioritized further

development of luvelta, it is seeking a potential partnership to realize its value. Sutro's lead

asset is STRO-004 (TF-targeting), which will have initial clinical data in mid-2026. Additionally,

in 2026, the company plans to submit INDs for STRO-006 (targeting integrin-beta 6) and from

its first dual-payload ADC program, STRO-227. Given the higher DARs, exatecan payload, and

novel technologies, these assets could demonstrate improved efficacy and safety compared to

competitors.

Base Case Assumptions Upside Scenario Downside Scenario

■ STRO-004 is successfully developed for ■ STRO-004 is successfully developed in ■ STRO-004's profile is not significantly

cervical cancer and achieves $375MM of additional tumor types beyond cervical differentiated than Tivdak in cervical

peak sales cancer cancer

■ The STRO-006 and STRO-227 preclinical ■ The preclinical assets fail in clinical

programs are successfully developed in development

solid tumors

■ XpressCF platform leads to new or