YB-800 ADCs Reach Important Milestone: Proof of Concept in Preclinical in Vitro and in Vivo Tests

RIEHEN, Switzerland, April 18, 2025 /PRNewswire/ — Ymmunobio AG (YB), a Swiss-based global biotech company dedicated to the development of new cancer therapeutics, is proud to announce that its two-antibody drug conjugate (ADC) assets, YB-800ADC1 and YB-800ADC2, have completed the preclinical proof of concept studies. Both in vivo and in vitro studies have reached this important milestone by demonstrating the anti-tumor efficacy of both ADCs.

The ADCs are derived from YB’s lead antibody YB-800 which targets a novel and first in class tumor marker. They utilize established payloads and a third-generation linker, demonstrating a tumor growth inhibition of 90%.

“These excellent results allow YB to move forward swiftly to prepare for the pivotal toxicology studies. This is a major step towards the clinical development of our ADCs in solid tumors and demonstrates the potential for YB’s ADCs to address unmet needs for cancer patients expressing the new novel tumor marker. In addition, the proof-of-concept data support the preclinical development of the two YB-800 based radiopharmaceuticals developed in collaboration with the Paul Scherer Institute,” said Peter Schiemann, CEO.

About Ymmunobio

Ymmunobio is at the forefront of oncology research, focusing on a novel target receptor for the treatment of solid tumors with high unmet need. Currently, in pre-clinical development, Ymmunobio’s research is dedicated to advancing three treatment options solid tumors, with their innovative Theranostic platform:

1. YB-800ADCs, 2. YB-800R (radiopharmaceutical; therapeutic & diagnostic) in collaboration with the Paul-Scherrer-Institute and 3. YB-800BiTEs featuring aCD3

For more information about supporting Ymmunobio’s initiatives, contact YB CEO Peter Schiemann at [email protected] or YBs communications team at [email protected], +41 (0) 76 378 59 30.

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