Seoul – September 12, 2026 -- SystImmune, Inc. announced that new global Phase 1 data support 2.5 mg/kg D1D8 Q3W as the recommended Phase 3 dose for iza-bren (izalontamab brengitecan), a bispecific EGFRxHER3 antibody drug conjugate, in previously treated EGFR-mutated metastatic non-small cell lung cancer (NSCLC).
Randomized Phase 1 cohort confirms higher efficacy at the 2.5 mg/kg dose level
The abstract, presented in an oral session at the IASLC 2026 World Conference on Lung Cancer (WCLC) in Seoul, South Korea, evaluated iza-bren across three dose levels in a randomized dose-expansion cohort. Patients enrolled had EGFR-mutated metastatic NSCLC and had previously received a third-generation EGFR inhibitor. Results showed promising antitumor activity with a manageable safety profile, with the highest efficacy observed at the 2.5 mg/kg dose.
Global data replicate efficacy and safety previously reported in Chinese patients
SystImmune said the randomized results demonstrated consistent efficacy and safety in a global patient population, mirroring findings shown earlier in Chinese cohorts. The company positions this consistency as key evidence supporting the drug's advancement into a global registrational trial.
Dose selection sets stage for IZABRIGHT-Lung01 registrational study
The 2.5 mg/kg D1D8 Q3W regimen will serve as the recommended Phase 3 dose for IZABRIGHT-Lung01, the global registrational study of iza-bren in EGFR-mutated NSCLC patients who progressed on a third-generation EGFR inhibitor. Jonathan Cheng, M.D., Chief Medical Officer of SystImmune, said the safety and pharmacokinetic findings, together with the dose-expansion efficacy data, mark "an important step forward as we advance the global registrational study."
Bristol Myers Squibb partnership backs bispecific ADC's clinical progression
Iza-bren (BL-B01D1) is being developed under a license and collaboration agreement between SystImmune and Bristol Myers Squibb. The ADC targets EGFR and HER3, two receptors highly expressed in epithelial cancers and linked to tumor cell proliferation and survival. Upon antibody-mediated internalization, the molecule releases a Topo1i payload designed to induce cytotoxic stress and cancer cell death.
The presentation, titled "Phase 1 Global Study of Iza-bren in Patients with Metastatic EGFR-mutated NSCLC: Results of the Randomized Dose Expansion Cohort," was delivered by Alexander Spira during the OA10 session on novel antibodies and ADCs at WCLC on September 14, 2026.