A novel antibody-drug conjugate (ADC), iza-bren (BL-B01D1), demonstrated encouraging safety and efficacy results in previously treated patients with EGFR-mutated non-small cell lung cancer (NSCLC), according to findings presented at the International Association for the Study of Lung Cancer (IASLC) 2025 World Conference on Lung Cancer (WCLC).
Iza-bren is a first-in-class EGFR x HER3 bispecific ADC linked to a novel topoisomerase I inhibitor payload (Ed-04). The drug was evaluated in two Phase I/II studies in patients with locally advanced or metastatic solid tumors, including EGFR-mutated NSCLC. Patients received a range of doses on different schedules, including day 1 and day 8 every 3-week cycle (D1D8 Q3W) and day 1 every 3-week cycle (D1 Q3W).
Among the 171 EGFR-mutated NSCLC patients, 50 patients who received prior TKI and chemo-naïve were treated at 2.5 mg/kg D1D8 Q3W. In this subgroup, the objective response rate (ORR) was 66.0%, the confirmed ORR (cORR) was 56.0%, the median progression-free survival (mPFS) was 12.5 months, the median duration of response (mDOR) was 13.7 months, and the median overall survival (mOS) was not reached with a 12-mo OS rate of 80.3%.
According to the lead investigator Dr. Wenfeng Fang from Sun Yat-sen University Cancer Center, Guangzhou, China, the safety profile was manageable. The most frequent hematologic treatment-related adverse events (TRAEs) were anemia (90.6%), leukopenia (80.7%), neutropenia (78.4%), and thrombocytopenia (74.3%). The most frequent non-hematologic TRAEs included nausea, alopecia, and asthenia. Only 1.2% of patients were discontinued due to TRAEs, and no treatment-related death was observed.
This early data suggests iza-bren may offer a promising treatment option for patients with EGFR-mutated NSCLC. Phase III registrational study of iza-bren as monotherapy in EGFR-mutated NSCLC after progression on a third generation TKI is ongoing in China."
Dr. Wenfeng Fang, Sun Yat-sen University Cancer Center, Guangzhou, China
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