BioNTech and Bristol Myers Squibb Report Positive Interim Phase 2 Data in Lung Cancer Immunotherapy Trial

BioNTech and Bristol Myers Squibb shared interim Phase 2 data on pumitamig plus chemotherapy in untreated extensive-stage small cell lung cancer patients. The regimen achieved a 76.3% confirmed overall response rate and a 100% disease control rate, with average tumor shrinkage of 56.7%. Median progression-free survival was 6.8 months. The safety profile was manageable with no new signals. A Phase 3 trial is underway comparing pumitamig plus chemotherapy against atezolizumab plus chemotherapy in first-line ES-SCLC.

BioNTech SE (Nasdaq: BNTX) and Bristol Myers Squibb Company (NYSE: BMY) have shared interim Phase 2 data on pumitamig, an investigational bispecific antibody targeting PD-L1 and VEGF-A, in combination with chemotherapy for untreated extensive-stage small cell lung cancer (ES-SCLC) patients. The data, presented at the IASLC 2025 World Conference on Lung Cancer in Barcelona, showed a 76.3% confirmed overall response rate (cORR) and a 100% disease control rate (DCR), with an average tumor shrinkage of 56.7%. Median progression-free survival (mPFS) was 6.8 months, and the safety profile was manageable with no new signals Press Release - BioNTech^[1].

The interim analysis included 43 patients with untreated ES-SCLC, who received pumitamig in combination with standard of care chemotherapy in two dose levels. Among 38 efficacy-evaluable patients, the confirmed overall response rate was 76.3% (85.0% at 20 mg/kg and 66.7% at 30 mg/kg), and the disease control rate was 100%. Median progression-free survival (mPFS) was 6.8 months (6.3 months at 20 mg/kg and 7.0 months at 30 mg/kg). Pumitamig plus chemotherapy showed a manageable safety profile, with no new safety signals and a discontinuation rate of 14% Press Release - BioNTech^[1].

The data support a global randomized Phase 3 trial, ROSETTA-LUNG-01 (NCT06712355), evaluating pumitamig plus chemotherapy versus atezolizumab plus chemotherapy as a first-line treatment in patients with untreated ES-SCLC. The pivotal trial is enrolling patients at clinical trial sites in the United States, the United Kingdom, Türkiye, China, the Republic of Korea, and Australia, with additional sites planned to open globally. Pumitamig received Orphan Drug designation from the U.S. Food and Drug Administration (FDA) for the treatment of patients with small cell lung cancer in 2025 Press Release - BioNTech^[1].

Small cell lung cancer (SCLC) accounts for 15% of all lung cancer cases, with an estimated 250,000 new cases globally per year. It is the most aggressive type of lung cancer, often spreading early to other parts of the body and developing resistance mechanisms, making it more challenging to treat. Platinum-based chemotherapy combined with etoposide chemotherapy has been the standard first-line treatment for decades. While the addition of immune checkpoint inhibitors to chemotherapy has shown improved survival outcomes for patients with advanced or extensive-stage disease, most patients progress within months after treatment, and the prognosis remains poor. The 5-year survival rate for patients with extensive-stage SCLC is only 5%, emphasizing the need for new treatment options that extend progression-free survival .

Pumitamig is a novel investigational bispecific antibody, jointly developed by BioNTech and BMS, combining two complementary, validated mechanisms in oncology into one single molecule. It combines PD-L1 checkpoint inhibition aimed at restoring T cells’ ability to recognize and destroy tumor cells with the neutralization of VEGF-A. The blocking of VEGF-A is aimed at reversing the tumor’s immunosuppressive effect in its microenvironment and cutting off the blood and oxygen supply that feeds tumor cells (anti-angiogenesis effect), with the intention of preventing the tumor from growing and proliferating. Pumitamig may be differentiated via its mechanism of action of targeting PD-L1 on tumor cells to localize anti-VEGF activity within the tumor microenvironment, aiming to enhance therapeutic precision and minimize systemic exposure .

BioNTech is a global next-generation immunotherapy company pioneering novel investigative therapies for cancer and other serious diseases. BioNTech exploits a wide array of computational discovery and therapeutic modalities with the intent of rapid development of novel biopharmaceuticals. Its diversified portfolio of oncology product candidates aims to address the full continuum of cancer, including mRNA cancer immunotherapies, next-generation immunomodulators, and targeted therapies such as antibody-drug conjugates (ADCs) and innovative chimeric antigen receptor (CAR) T cell therapies. Based on its deep expertise in mRNA development and in-house manufacturing capabilities, BioNTech and its collaborators are researching and developing multiple mRNA vaccine candidates for a range of infectious diseases alongside its diverse oncology pipeline .

In summary, the interim Phase 2 data on pumitamig plus chemotherapy for ES-SCLC patients show encouraging results, with a high response rate and manageable safety profile. The ongoing Phase 3 trial will further evaluate the potential of pumitamig as a new treatment option for patients with extensive-stage small cell lung cancer.