SystImmune to Present Promising Data on Iza-bren at WCLC

SystImmune, Inc., a clinical-stage biotechnology company based in Redmond, Washington, will present new global data on its investigational drug iza-bren (izalontamab brengitecan) at the International Association for the Study of Lung Cancer (IASLC) 2026 World Conference on Lung Cancer (WCLC) in Seoul, South Korea, from September 12 to 15.

The data, derived from a randomized dose-expansion cohort of the drug, shows promising antitumor activity and a tolerable safety profile. The results support the selection of 2.5 mg/kg D1D8 Q3W as the recommended Phase 3 dose for iza-bren in previously treated EGFR-mutated metastatic non-small cell lung cancer (NSCLC). This dose level demonstrated increased efficacy compared to lower dose levels, while maintaining a manageable safety profile.

Iza-bren is a bispecific antibody drug conjugate (ADC) that targets both EGFR and HER3, two proteins highly expressed in various epithelial cancers. The dual mechanism of action of iza-bren blocks EGFR and HER3 signals, reducing proliferation and survival signals in cancer cells. Upon internalization, the Topo1i payload, a novel therapeutic agent, is released, causing cytotoxic stress and leading to cancer cell death.

The Phase 1 global study evaluated iza-bren in a randomized expansion cohort of patients with EGFR-mutated metastatic NSCLC who had previously received a third-generation EGFR inhibitor. The study included three dose levels, with the 2.5 mg/kg dose level showing the highest efficacy. The data also confirmed the consistent efficacy and safety profile observed in a global population, similar to findings in a previous Chinese patient cohort.

Jonathan Cheng, M.D., Chief Medical Officer of SystImmune, commented, "The data being presented at WCLC provide important insights into the clinical profile of iza-bren in global patients with previously treated EGFR-mutated metastatic NSCLC. We are encouraged by the promising antitumor activity observed in this randomized dose-expansion cohort, including the increased efficacy at the 2.5 mg/kg dose level. Together with the safety and pharmacokinetic findings, these results support 2.5 mg/kg D1D8 Q3W as the recommended Phase 3 dose and represent an important step forward as we advance the global registrational study, IZABRIGHT-Lung01, in patients with EGFR-mutated NSCLC following progression on a third-generation EGFR inhibitor."

SystImmune is developing iza-bren under a license and collaboration agreement with Bristol Myers Squibb. The company's focus on bi-specific, multi-specific antibodies and ADCs aims to advance innovative cancer treatments. The ongoing clinical trials and robust preclinical pipeline represent cutting-edge biologics development in the field of oncology.