YB-800 / Ymmunobio - LARVOL DELTA

YB-811, a novel antibody drug conjugate targeting the tumor-selective human neuronal pentraxin receptor shows pronounced efficacy in experimental tumor models (AACR 2026) - "Recent immunohistochemistry studies performed with a fully humanized monoclonal antibody (YB-800) targeting NPTXR with high affinity have revealed expression of membrane-associated NPTXR protein in a wide variety of solid tumors (but not in adjacent healthy tissues and healthy tissue samples) with a high prevalence (up to 98%) and H-scores (up to 300); e.g., in bladder, cervix, non-TNBC, NSCLC, and pancreas tumor samples. Results clearly indicate concentration- and time-dependent effect on tumor cell proliferation and survival, as well as pronounced anti-tumor activity - tumor growth inhibition/regression - in established tumor-bearing athymic mice. Taken together, these results strongly support further exploration of the potential therapeutic benefit of YB-811."

ADC • Preclinical • Lung Cancer • Non Small Cell Lung Cancer • Oncology • Pancreatic Cancer • Solid Tumor • Triple Negative Breast Cancer

PCO25-210: Design of Novel Antibody Drug Conjugates Using a Fully Humanized Monoclonal Antibody Targeting the Human Neuronal Pentraxin Receptor (YB800-ADCs) for Therapeutic Intervention in Oncology. (PubMed, J Natl Compr Canc Netw) - No abstract available

Journal • Oncology

Ymmunobio and PSI Secure Innosuisse Grant to Advance Radio-pharmaceutical YB-800 (PRNewswire) - "Ymmunobio (YB) is excited to share that they in collaboration with the Paul Scherrer Institute (PSI) have received Innosuisse support to develop innovative radioactive loaded antibodies for the treatment and diagnostic of solid tumors based on YBs proprietary YB-800. The Innosuisse support validates Ymmunobio's approach to targeted solid tumor therapy using a new and first in class target with a high prevalence in cancer patients....The newly developed antibodies will utilize a linker attached to YB-800, capable of carrying any radioactive isotope for the treatment and diagnostic of solid tumors. Ymmunobio plans to leverage this cutting-edge technology to treat patients with solid tumors who express the new marker."

Financing • Solid Tumor

YB-800, a monoclonal antibody targeting the human neuronal pentraxin receptor (NPTXR), as a potential candidate for the design of a first in class antibody drug conjugate (ADC) as novel therapeutic intervention in gastro-intestinal cancers. (ASCO 2024) - "In conclusion, YB-800 represents a first in class ADC candidate that could be used as novel treatment for gastro-intestinal cancers. Hence, as initial proof of concept, tesirine (DNA intercalating agent) and deruxtecan (topoisomerase I inhibitor) containing protease-sensitive linkers were coupled to YB-800 by stochastic maleimide conjugations to interchain cysteines. Initial results with YB-800-based ADCs will be discussed."

Cervical Cancer • Colorectal Cancer • Endocrine Cancer • Gastric Cancer • Gastrointestinal Cancer • Hepatocellular Cancer • Oncology • Solid Tumor • Thyroid Gland Carcinoma

Ymmunobio Signs Transfer Ownership Agreement with Nagoya University for NPTXR Antibodies (PRNewswire) - "Ymmunobio AG...has secured ownership to neuronal pentraxin receptor (NPTXR) antibodies, which have shown utility for developing therapeutics and for novel diagnostic tools in the treatment of several gastro-intestinal cancers, including gastric cancer. Ymmunobio has begun developing the lead, fully humanized and first-in-class NPTXR antibody, YB-800, which has demonstrated anti-tumor activity in vivo and in vitro for solid tumors, including several gastro-intestinal and breast cancers."

Licensing / partnership • Breast Cancer • Gastric Cancer • Gastrointestinal Cancer • Oncology • Solid Tumor