SystImmune and Bristol Myers Squibb have announced a major breakthrough in the fight against triple-negative breast cancer, reporting that izalontamab brengitecan (iza-bren) significantly extended survival in a pivotal Phase III trial.

 

The topline results, reported by SystImmune’s parent company Sichuan Biokin Pharmaceutical, come from a pre-specified interim analysis of the BL-B01D1-307 study in patients with unresectable locally advanced or metastatic triple-negative breast cancer (TNBC) whose disease had progressed after prior taxane therapy.

 

Iza-bren met both dual primary endpoints, delivering statistically significant and clinically meaningful improvements in progression-free survival (PFS) and overall survival (OS) compared with chemotherapy of physician’s choice.

 

The study marks the third Phase III success for the EGFR×HER3 bispecific antibody-drug conjugate — and the first time a bispecific ADC has reported dual positive PFS and OS results in a Phase III trial for TNBC.

 

“Patients with advanced triple-negative breast cancer who progress after standard therapies face an urgent need for more effective options,” said Dr. Yi Zhu, Chief Executive Officer of Biokin “These topline results further strengthen our confidence in iza-bren’s potential to deliver meaningful clinical benefit across multiple cancers.”

 

“These results underscore the potential of bispecific ADC technology targeting both EGFR and HER3 to meaningfully change outcomes in difficult-to-treat cancers,” said Cristian Massacesi, Executive Vice President, Chief Medical Officer and Head of Development at Bristol Myers Squibb. “We look forward to advancing the science and development of ADCs, with the hope of uncovering new options for people living with cancer.”

 

The BL-B01D1-307 study is sponsored by Biokin in Mainland China. Outside of China, iza-bren is being jointly developed by SystImmune and Bristol Myers Squibb under a collaboration and exclusive license agreement.

 

Regulators are taking notice. The Center for Drug Evaluation under China’s National Medical Products Administration has granted Breakthrough Therapy Designation to iza-bren for seven indications. The U.S. Food and Drug Administration has also granted Breakthrough Therapy Designation for previously treated non-small cell lung cancer patients with an EGFR mutation.