Sutro Biopharma to Host Virtual Research & Development Day on November 12, 2025

Sutro Biopharma, Inc. (Sutro or the Company) (NASDAQ: STRO), an oncology company pioneering site-specific and novel-format antibody drug conjugates (ADCs), today announced that it will host a virtual Research & Development Day, highlighting the details of its platform innovation and next-generation ADC pipeline.

The live webcast will be held on Wednesday, November 12, 2025, starting at 7:00AM PT / 10:00AM ET.

Webcast Information: To access the live audio webcast, please go to https://ir.sutrobio.com/news-events/ir-calendar . An archived replay of the webcast will be available on the Company’s website following the event.

About Sutro Biopharma Sutro Biopharma, Inc. is 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 .

Investor Contact Emily White Sutro Biopharma (650) 823-7681 [email protected]

Media Contact Amy Bonanno Lyra Strategic Advisory [email protected]