Boehringer Ingelheim and BioNTech launch a Phase Ib/II trial evaluating obrixtamig plus pumitamig, a dual bispecific immunotherapy combination, in extensive-stage small cell lung cancer
Written By: Chikkula Pavan Kumar, PharmD
Reviewed By: Pharmacally Editorial Team
Phase Ib/II Collaboration Targets Aggressive Small Cell Lung Cancer
Boehringer Ingelheim announced a clinical trial collaboration with BioNTech to evaluate a novel immuno-oncology combination in extensive-stage small cell lung cancer (ES-SCLC). BioNTech will supply pumitamig (BNT327/BMS-986545), a PD-L1/VEGF-A bispecific antibody jointly developed with Bristol Myers Squibb, while Boehringer Ingelheim will serve as regulatory sponsor of the Phase Ib/II study.
The trial will assess safety, tolerability, and early clinical activity of obrixtamig (BI 764532), Boehringer Ingelheim’s investigational DLL3/CD3 T-cell engager, in combination with pumitamig.
Itziar Canamasas, Global Head of Oncology at Boehringer Ingelheim said the combination is designed to overcome immune evasion and the immunosuppressive tumor environment in SCLC, with the goal of delivering more durable clinical benefit for patients.
Dual Mechanism Aims to Overcome Immune Resistance
Small cell lung cancer accounts for about 15–20% of lung cancers and is characterized by rapid progression and early relapse. The combination targets complementary pathways: obrixtamig redirects T-cells to kill DLL3-expressing tumor cells, while pumitamig blocks PD-L1 and VEGF-A to restore immune activity and inhibit tumor angiogenesis.
Boehringer Ingelheim stated that combining DLL3-directed T-cell redirection with PD-L1 and VEGF pathway modulation is intended to address immune evasion and an immunosuppressive tumor microenvironment in ES-SCLC.
Supporting Clinical Data for Both Investigational Agents
In the Phase I DAREON-8 study (NCT06077500), obrixtamig plus chemotherapy and atezolizumab achieved a 68% confirmed objective response rate and 89% disease control rate, with a 9-month progression-free survival rate of 52%.
The program is advancing into the Phase III DAREON-Lung-1 trial (NCT07472517) and has received Fast Track and Orphan Drug designations from the U.S. Food and Drug Administration, along with Orphan Drug status from the European Commission.
Pumitamig demonstrated a 76.3% confirmed objective response rate, 100% disease control rate, and median progression-free survival of 6.8 months in a Phase II ES-SCLC study (NCT06449209) with chemotherapy. The program has advanced into the Phase III ROSETTA LUNG-01 trial (NCT06712355) and received FDA Orphan Drug Designation in 2025.
Study Initiation Planned for 2026
Under the non-exclusive agreement, BioNTech will supply pumitamig and Boehringer Ingelheim will act as regulatory sponsor, with both companies retaining rights to their assets. Patient dosing is expected to begin in the second half of 2026.
Reference
Boehringer Ingelheim to evaluate innovative combination of DLL3‑targeting T‑cell engager plus PD‑L1/VEGF‑A bispecific antibody in small cell lung cancer, 09 April 2026, Boehringer-BioNTech partnership to advance SCLC therapy | Boehringer Ingelheim
About the Writer
Chikkula Pavan Kumar, PharmD is a Doctor of Pharmacy with a keen interest in clinical pharmacy, pharmacovigilance, and evidence-based practice. In his words, he is passionate about patient safety and translating complex medical information into clear, research-driven communication.