Oxford BioTherapeutics’ third partnered programme with Boehringer Ingelheim enters the clinic and its first (Obrixtamig) advances to Phase 3

• First patients dosed with BI 3820768 (OB33), marking third programme from the Oxford BioTherapeutics (OBT)-Boehringer Ingelheim collaboration to enter clinical development
• Obrixtamig reaches late-stage development triggering milestone payment
• Continued clinical progress across the partnered programmes demonstrates the strength and productivity of the long-standing OBT–Boehringer Ingelheim collaboration

Oxford, UK, and San Jose, California, 22 June 2026 – Oxford BioTherapeutics (“OBT”), a clinical-stage oncology company specialising in proteomics-driven target discovery for antibody-based therapies enabled by its OGAP®-Verify platform, today announced two new clinical milestones with Boehringer Ingelheim-partnered programmes, BI 3820768 (OB33) and obrixtamig (OBT620).

BI 3820768 is the third programme from OBT’s multi-target collaboration with Boehringer Ingelheim to achieve first-patient dosing (A Study to Test How Well Different Doses of BI 3820768 Are Tolerated by People With Advanced Cancer (Solid Tumours) - NCT07306559), triggering a milestone payment to OBT. The BI 3820768 target was identified using OBT’s proprietary OGAP®-Verify platform and represents the second development milestone for this programme, following the initiation of IND-enabling studies one year earlier.

Further illustrating the strength and maturity of the collaboration, OBT also highlighted the advancement of obrixtamig (OBT620), an investigational DLL3-targeting bispecific T-cell engager originating from its discovery platform. Obrixtamig has entered global Phase 3 development in two trials: DAREON®-Lung-1 is investigating obrixtamig in combination with chemotherapy and atezolizumab versus chemotherapy and atezolizumab in previously untreated extensive-stage small cell lung cancer, where the first patients have recently been dosed. DAREON®-NEC-1 is evaluating obrixtamig in combination with chemotherapy versus chemotherapy alone as first-line treatment for patients with DLL3-positive unresectable locally advanced or metastatic extrapulmonary neuroendocrine carcinoma. A second Boehringer Ingelheim-partnered programme from OBT’s work, the investigational B7-H6-targeting T-cell engager BI 765049, is also in clinical development for advanced solid tumours.

DLL3 was originally identified by OBT using its OGAP®-Verify platform as a tumour-selective T-cell engager target. The antigen is expressed in approximately 80–85% of small cell lung cancer and certain neuroendocrine carcinomas, supporting its potential as a promising therapeutic target in aggressive cancers with high unmet need.

The collaboration began in 2013 and was subsequently expanded in 2020 and 2023. OBT has applied its OGAP®-Verify platform to identify novel oncology targets in solid tumours. The partnership has generated multiple development-stage assets, including three clinical programmes and a fourth target optioned in January 2025.

Christian Rohlff, PhD, Chief Executive Officer of OBT, said: “Establishing another clinical-stage programme with BI 3820768 further validates the robustness of our OGAP®-Verify discovery platform and the quality of the oncology targets it delivers. The fact that three of the four programmes optioned by Boehringer Ingelheim have now entered the clinic underscores the strength and productivity of this longstanding collaboration. In parallel, the advancement of obrixtamig into Phase 3 highlights the long-term value-creation potential of our platform and our ability to translate novel targets into clinically advanced therapies for patients with high unmet need.”

Vittoria Zinzalla, Global Head of Experimental Medicine at Boehringer Ingelheim, said: “Our long-standing collaboration with Oxford BioTherapeutics demonstrates the value of linking complementary scientific expertise to transform outcomes for people living with difficult-to-treat cancers. By combining OBT’s strength in target discovery with our expertise in therapeutic antibody development, we connect insights across the R&D continuum, advancing differentiated treatment approaches while strengthening a more efficient and connected oncology ecosystem to create unprecedented impact.”

OBT’s OGAP®-Verify platform enables highly sensitive and precise target identification, supporting the development of differentiated antibody-based therapies and the successful progression of multiple programmes into clinical development.

Under the collaboration, Boehringer Ingelheim is responsible for global development and commercialisation of all programmes.