#United States #SystImmune #Redmond #Iza-bren #Bristol Myers

SystImmune and Bristol Myers Squibb Announce First Global Phase I Results for Iza-bren

In a significant breakthrough, SystImmune, Inc., a biotechnology firm focused on clinical-stage treatments, and Bristol Myers Squibb (BMS) revealed the first global results from their Phase I study on Iza-bren, a novel bispecific antibody-drug conjugate (ADC) targeting both EGFR and HER3. This study was presented on October 17, 2025, at the European Society for Medical Oncology (ESMO) Congress, held in Berlin, Germany.

Iza-bren is poised to become a potentially first-in-class treatment option for patients suffering from advanced solid tumors, particularly those with non-small cell lung cancer (NSCLC). The development of Iza-bren is part of a collaboration between SystImmune and BMS that spans territories outside of mainland China. Notably, in August 2025, the U.S. FDA granted the drug breakthrough therapy designation for patients with previously treated EGFR-mutated NSCLC, following promising data observed in studies conducted in China.

Study Overview and Results

The Phase I US-Lung-101 study (NCT05983432) assessed over 100 patients with heavily pre-treated metastatic or unresectable advanced NSCLC and other solid tumors. At the conclusion of data gathering on July 23, 2025, findings indicated not only promising antitumor activity across various tumor types, including both EGFR mutant and wildtype NSCLC but also a manageable safety profile.

Efficacy Findings:
Among 20 patients receiving a dose of 2.5 mg/kg, about 55% (11 out of 20) showed confirmed responses, with a median progression-free survival (PFS) of 5.4 months. Positive response rates were noted not just in those with EGFR mutations but also in patients without mutations.

Safety Profile:
The study identified blood-related side effects such as neutropenia, which were effectively managed using standard medical interventions. Significantly, no cases of interstitial lung disease were reported, addressing prior concerns about drug-induced pulmonary toxicity. Future trials will implement mandatory preventive measures for such effects to ensure patient safety.

Future Directions

With ongoing global studies on initial indications such as triple-negative breast cancer and urothelial cancer, the next phases of the research aim to confirm Iza-bren’s effectiveness across broader patient demographics. The Chief Medical Officer of SystImmune, Dr. Jonathan Cheng, expressed optimism about the drug's potential, stating, "The first global presentation of Iza-bren builds on the compelling data initially observed in Chinese patients, showing consistent efficacy in a heavily pre-treated global population."

BMS's Senior Vice President for Development, Anne Kerber, echoed this sentiment, emphasizing their commitment to developing innovative therapies for challenging cancers. The promising results seen in early studies bolster the belief in Iza-bren’s potential and signal robust plans for upcoming registrational studies in multiple cancer types.

About SystImmune and Bristol Myers Squibb

SystImmune is dedicated to creating innovative cancer treatments, specializing in bi-specific and multi-specific antibody-drug conjugates. Based in Redmond, WA, and Princeton, NJ, the company holds a rich pipeline of clinical and preclinical assets aimed at combating various forms of cancer.

Bristol Myers Squibb, recognized for its contributions to biopharmaceutical advancements, strives to deliver innovative medicines for serious diseases and cancer therapy. The collaborative efforts between SystImmune and BMS represent a significant stride towards achieving effective treatment solutions for patients grappling with complex malignancies.

Conclusion

The presentation of Iza-bren’s Phase I results underscores a promising advancement in cancer therapy that could redefine treatment protocols for patients facing advanced solid tumors. As researchers continue to unveil the therapeutic potential of Iza-bren, both SystImmune and BMS remain steadfast in their goal to enhance patient outcomes through innovative medical solutions.