SystImmune Inc. and Bristol Myers Squibb announced that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation (BTD) to izalontamab brengitecan (iza-bren) for the treatment of locally advanced or metastatic non-small cell lung cancer (NSCLC) with specific EGFR mutations in patients whose disease has progressed following EGFR tyrosine kinase inhibitor (TKI) therapy and platinum-based chemotherapy.
Iza-bren is a potential first-in-class bispecific antibody-drug conjugate (ADC) that targets both EGFR and HER3 receptors, delivering a topoisomerase 1 inhibitor payload directly to cancer cells. The drug is being developed in China by Biokin and co-developed globally by SystImmune and Bristol Myers Squibb under a collaborative agreement.
The FDA’s decision to grant BTD was based on positive safety and efficacy data from three ongoing clinical trials: two China-based studies (BL-B01D1-101 and BL-B01D1-203) and a global trial (BL-B01D1-LUNG-101) being conducted across the U.S., Europe, and Japan. In these studies, iza-bren has shown encouraging signs of efficacy and a manageable safety profile in patients with EGFR-mutant NSCLC who have exhausted existing treatment options.
While EGFR TKIs offer benefits in the initial treatment of NSCLC, most patients experience disease progression within 18 months. Current second-line treatments, such as platinum-based chemotherapy, often show limited effectiveness and come with significant side effects — highlighting the urgent need for better alternatives.
“The FDA’s granting of Breakthrough Therapy Designation underscores the potential of iza-bren to meaningfully improve clinical outcomes,” said Dr. Jonathan Cheng, Chief Medical Officer of SystImmune. “We look forward to advancing clinical development in collaboration with the FDA to bring this promising therapy to patients.”
The Breakthrough Therapy Designation is intended to expedite the development and review of treatments that may offer substantial improvement over current standard therapies for serious or life-threatening conditions.