Bristol Myers Squibb and SystImmune have announced that positive results from studies evaluating a bispecific antibody-drug conjugate (ADC) have been reported by SystImmune’s parent company.
Sichuan Biokin Pharmaceutical Co (Biokin), the parent company, reported positive results from prespecified interim analyses of two phase 3 studies evaluating izalontamab brengitecan (iza-bren), an investigational and potentially first-in-class EGFRxHER3 bispecific antibody-drug conjugate (ADC).
The ADC has now demonstrated clinical benefit in three phase 3 trials in China, underscoring its broad therapeutic potential in multiple tumour types.
The studies demonstrated iza-bren achieved statistically significant and clinically meaningful improvements in overall survival (OS) and progression-free survival (PFS) in heavily pretreated, unresectable locally advanced or metastatic triple-negative breast cancer (TNBC; PANKU-Breast02) and recurrent or metastatic oesophageal squamous cell carcinoma (ESCC; PANKU-Esophagus01). The data, presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting, supports iza-bren’s potential as a new standard of care in these challenging cancer types.
Iza-bren has now shown clinical benefit in three phase 3 trials, underscoring its broad therapeutic potential. PANKU-Breast02 is the first phase 3 study of a bispecific ADC to report positive results for dual primary endpoints of both PFS and OS in TNBC, while PANKU-Esophagus01 marks the first phase 3 trial of a bispecific ADC in oesophageal cancer to report positive dual primary endpoints of both PFS and OS. Iza-bren previously demonstrated positive phase 3 results in recurrent or metastatic nasopharyngeal carcinoma (NPC), presented at ESMO 2025.
Yi Zhu, CEO of Biokin, SAID: “As a potentially first-in-class EGFRxHER3 bispecific antibody-drug conjugate, iza-bren has now shown significant clinical benefit in three phase 3 trials in different cancer types, and the strength of the data presented at ASCO further reinforces the value iza-bren can deliver over current standards of care.”
Cristian Massacesi, executive vice president, chief medical officer and head of development at Bristol Myers Squibb, said: “Iza-bren can address a critical gap for patients who develop resistance or experience disease progression after prior therapies and may also hold potential in earlier lines of therapy.
“We have a broad development program for iza-bren and believe it has the potential to be a cornerstone treatment in a number of different cancers and easily combined with other therapies.”