OSE Immunotherapeutics (OSE) Status update summary

Pipeline and Clinical Development Overview

• Tedopi, a ready-to-use neoepitope-based immunotherapy vaccine, has treated over 700 patients and is in advanced clinical development for NSCLC and ovarian cancer, with additional Phase 2 studies in pancreatic cancer expected to read out in 2026.

• Lusvertikimab, a first-in-class, non-internalizing anti-IL-7R mAb, showed strong efficacy and safety in refractory IBD and chronic pouchitis, with a subcutaneous formulation in development and Phase 2 in pouchitis starting H2 2026.

• Multiple investigator-sponsored studies are ongoing, including a recent ovarian cancer trial presented at ASCO.

• Multiple partnered assets in immunology and oncology are in development, including collaborations with Boehringer Ingelheim and Veloxis.

NSCLC Treatment Landscape and Unmet Needs

• NSCLC remains the leading cause of cancer-related death, with most cases diagnosed at an advanced stage and a five-year survival rate of only 28%.

• Immunotherapy has improved outcomes, but only a minority of patients achieve long-term survival, and most do not respond durably.

• Standard second-line therapy, docetaxel, offers poor efficacy and significant toxicity, highlighting the need for better options.

Tedopi Clinical Data and Trial Updates in NSCLC

• Tedopi targets HLA-A*02 positive NSCLC patients, representing about 45% of the population, and is administered subcutaneously every three weeks.

• Phase II data showed a median overall survival of 17.3 months in pre-treated patients, with survival correlating to immune response against neoepitopes.

• The phase III ATALANTE-1 trial, stopped early due to COVID-19, showed Tedopi improved overall survival (11.1 vs. 7.5 months; HR 0.59) and had a better safety profile than docetaxel.

• Tedopi® demonstrated a 41% reduction in risk of death versus standard chemotherapy in Phase 3.

• The ongoing Phase 3 ARTEMIA trial in HLA-A2+ NSCLC has a futility analysis in Q3 2026 and final readout in Q1 2028, with overall survival as the primary endpoint.