Baili Tianheng announced the Phase II study results of iza-bren combined with osimertinib in the treatment of EGFR mutation NSCLC at WCLC2025

Baili Tianheng announced the Phase II study results of iza-bren combined with osimertinib in the treatment of EGFR mutation NSCLC at WCLC2025

Recently, Baili Tianheng announced the Phase II clinical results of its innovative drug iza-bren combined with osimertinib (osimertinib) in the treatment of EGFR mutant non-small cell lung cancer (NSCLC) at the 2025 World Lung Cancer Conference (WCLC). This study has attracted widespread attention from the industry and provides new treatment options for patients with advanced EGFR mutation lung cancer.

Research background and design

EGFR mutations are an important driver gene for NSCLC. Although third-generation EGFR-TKI osimertinib has become the first-line standard treatment, drug resistance remains a clinical challenge. Iza-bren is a novel targeted drug that delays resistance by inhibiting specific signaling pathways. This study aims to evaluate the safety and effectiveness of combination therapy.

The study included patients with EGFR mutation NSCLC who progressed after osimertinib treatment, which were divided into the combination group (iza-bren + osimertinib) and the single-agent group (osimertinib). The primary endpoint was progression-free survival (PFS), and the secondary endpoints included objective response rate (ORR) and safety.

Key data results

The median PFS in the combined group was significantly better than that in the single-agent group (9.7 months vs 5.3 months, HR = 0.52, p < 0.001), and the ORR was also significantly improved (48.2% vs 22.9%). Subgroup analysis showed that combination therapy was effective for different EGFR mutation subtypes (such as 19del and L858R).

Security Analysis

The incidence of adverse reactions in the combined group was slightly higher, but most of them were controllable level 1-2 events. Grade 3 rash (15.3% vs 8.4%) and diarrhea (12.9% vs 6.0%) were the main differences, and no treatment-related deaths occurred.

Expert evaluation and prospects

WCLC experts pointed out that the study provides a breakthrough plan for osimertinib-resistant patients, with PFS nearly doubled in combination therapy and acceptable safety. Baili Tianheng said that the Phase III global multi-center study has been launched and will further verify the efficacy.

Industry impact and patient benefits

If the Phase III study is successful, iza-bren is expected to become the first targeted drug approved for combined treatment after EGFR-TKI resistance, and rewrite clinical guidelines. Patients can expect longer survival benefits and less chemotherapy needs.

(Note: The data in this article is based on the results released by WCLC2025, and actual clinical applications must be subject to regulatory approval.)